Wegman report released

Update (Steve): I’ve read the Wegman Report and it’s obviously very gratifying. I won’t be able to provide a review for about a week as we’ve got a family reunion this week-end with two of my sisters and their families arriving from Colorado and B.C. , plus I’ve got to do some preparation for next week. It’s not that I don’t have anything to say about it.

John A: The report mentioned in today’s WSJ article has been released on the House Energy Committee’s website. The full report is here and the shorter factsheet is here

The Chairman of the Committee on Energy and Commerce as well as the Chairman of the Subcommittee on Oversight and Investigations have been interested in an independent verification of the critiques of Mann et al. (1998, 1999) [MBH98, MBH99] by McIntyre and McKitrick (2003, 2005a, 2005b) [MM03, MM05a, MM05b] as well as the related implications in the assessment. The conclusions from MBH98, MBH99 were featured in the Intergovernmental Panel on Climate Change report entitled Climate Change 20013: The Scientific Basis. This report concerns the rise in global temperatures, specifically during the 1990s. The MBH98 and MBH99 papers are focused on paleoclimate temperature reconstruction and conclusions therein focus on what appear to be a rapid rise in global temperature during the 1990s when compared with temperatures of the previous millennium. These conclusions generated a highly polarized debate over the policy implications of MBH98, MBH99 for the nature of global climate change, and whether or not anthropogenic actions are the source. This committee, composed of Edward J. Wegman (George Mason University), David W. Scott (Rice University), and Yasmin H. Said (The Johns Hopkins University), has reviewed the work of both articles, as well as a network of journal articles that are related either by authors or subject matter, and has come to several conclusions and recommendations. This Ad Hoc Committee has worked pro bono, has received no compensation, and has no financial interest in the outcome of the report.

JohnA, the first pdf downloads as blank for me.
The second one came out ok.

Report Raise “new” questions:

quote: A social network analysis that revealed that the small community of paleoclimate researchers appear to review each others work, and reuse many of the same data sets which calls into question the independence of peer-review and temperature reconstruction.

quote: It is clear that many of the proxies are re-used in most of the papers. It is not surprising that the paper would obtain similar results and so cannot really claim to be independent verifications.

The report could have used an editor and/or more skilled writer (it seemed a bit rushed and cursory in some areas, and bit unfocused), but the qualifications of the authors, and the bluntness of the assessment, should give pause to some.

If nothing else in pins the support of three well qualified statisticans to M&M’s work. It also provides nice summaries of social networks and each of the studies. Hopefully some of these fellows will remain interested in the subject and continue to offer advice.

A welcome development. The Mann team will likely reply “They did not show our conclusions as wrong, therefore we stand by our work”.

Wegman definitely supports M&M’s work and didn’t hold back on their critism in the climate field. The social networking diagrams are new to me.

From page 29 of the main report:

We have been to Michael Mann’s University of Virginia website and downloaded the materials there. Unfortunately, we did not find adequate material to reproduce the MBH98 materials.
We have been able to reproduce the results of McIntyre and McKitrick (2005b)

From page 48:

In general, we find the criticisms by MM03, MM05a and MM05b to be valid and their arguments to be compelling. We were able to reproduce their results and offer both theoretical explanations (Appendix A) and simulations to verify that their observations were correct. We comment that they were attempting to draw attention to the deficiencies of the MBH98-type methodologies and were not trying to do paleoclimatic temperature reconstructions8

From page 49:

Generally speaking, the paleoclimatology community has not recognized the validity of the MM05 papers and has tended dismiss their results as being developed by biased amateurs. The paleoclimatology community seems to be tightly coupled as indicated by our social network analysis, has rallied around the MBH98/99 position, and has issued an extensive series of alternative assessments most of which appear to support the conclusions of MBH98/99.

Recommendation 4. Emphasis should be placed on the Federal funding of research related to fundamental understanding of the mechanisms of climate change. Funding should focus on interdisciplinary teams and avoid narrowly focused discipline research.

My reading is that funding should go to basic physical and chemical research.

I have just read the report and will need to do so again. Several things strike me. First it is written with a clarity that many of us would do well to follow. It uses clear examples, and illustrates these with diagrams and elegant discussions that you don’t need to be a statistician to follow. Second, the authors have a very clear grasp of the nature of the science and proxies that would put many a scientist to shame.

I think this is an important document that highlights many inadequacies in the way we pursue publicly funded science. It throws open for all to see the social networks at the heart of science, impacts on peer review at both the grant awarding and publication stages, and the way scientists gain esteem amongst their peers.

The committee has examined the facts and formed a surprisingly thorough analysis of the situation. The detailed review of the Hockey Team and its group-think is amazing. The utter failure of peer review must give pause to the leading publications. Do they dare continue with business as usual?

Dueling blogs may not be the appropriate media for “science” but I doubt that this stunning report would have occurred without them.

“They did not show our conclusions as wrong, therefore we stand by our work”.

Actually, they did, and they did it in such a blunt manner that Mann, et. al. will be hard pressed to dodge this one. Of course, this will become “a politically motivated attack”, but hey, it’s not like they didn’t start the political debate by using the IPCC as their sounding board.

Re #7: “Yes I noticed a typos, and if I notice them there must be more.”

The typos will be used by the AGW crowd to try and undercut the report in the mass media. The report will be spun as useful addition in creating a sustainable consensus on the impending climate change catastrophe.

No matter, the Wegman report is complete vindication for M & M. And a nail in the coffin of AGW. A M & M style debunking of the GCM’s would collapse AGW groupthink. The GCM’s are ripe for picking apart and devouring. Hopefully, Barton will start an investigation into GCM’s.

Reid, I do not agree that this is a nail in the coffin in AGW. It’s a severe criticism of the Team. But there are other important arguments for AGW. I don’t think that anyone should approach such matters with a view to debunking – I didn’t – but to understand the issues and accept what needs to be accepted and debunk what needs to be debunked.

Peter H, I agree that one has to be as cautious with reports that support you as reports that criticize you. Just because someone agrees with you doesn’t mean that they’re right. However, it doesn’t mean that they’re wrong either.

re #16: Yes it should be fought out in the journals. But the peer review process doesn’t always allow this. One aspect not touched on by the social network analysis in the report is just how difficult it is for an ‘outsider’ to get his work through peer review, when all the reviewers are playing for the same team.

Actually, Steve, I agree that it is a nail in the coffin for “A”GW. There is plenty of evidence for GW, certainly, and some analytical proof that there is an anthropogenic influence on climate. However, the HS was the PRIMARY link between man-made pollutants and warming (if you really want to buy into the CO2 as a pollutant idea). Cause and effect was established by these studies, albeit incorrectly. Removing them from consideration certainly removes the A from AGW (even if it turns out to be true in the future).

Mann et al., misused certain statistical methods in their studies, which inappropriately produce hockey stick shapes in the temperature history. Wegman’s analysis concludes that Mann’s work cannot support claim that the1990s were the warmest decade of the millennium.
Report: “Our committee believes that the assessments that the decade of the 1990s was the hottest decade in a millennium and that 1998 was the hottest year in a millennium cannot be supported by the MBH98/99 analysis. As mentioned earlier in our background section, tree ring proxies are typically calibrated to remove low frequency variations. The cycle of Medieval Warm Period and Little Ice Age that was widely recognized in 1990 has disappeared from the MBH98/99 analyses, thus making possible the hottest decade/hottest year claim. However, the methodology of MBH98/99 suppresses this low frequency information. The paucity of data in the more remote past makes the hottest-in-a-millennium claims essentially unverifiable.”

Re:
“This committee does not believe that web logs are an appropriate forum for the scientific debate on this issue.”

I think they could be talking about RC in that statement just as well. That was my question to my own representatives whom I wrote a long time ago and I gave links to both RC and to CA and asked them to read both. Like Gavin, for example who works for NASA at points in time. There’s a big difference between Steve and a NASA employee having a web log.

One aspect not touched on by the social network analysis in the report is just how difficult it is for an “outsider’ to get his work through peer review, when all the reviewers are playing for the same team.

I think one can infer such a conclusion from the analysis of the mutual-admiration concept, however. Perhaps that should be brought up in the Barton hearing?

1. The peer review process has not stopped Steve from publishing. Steve just hasn’t written the papers.

2. The blog and the papers should not be looked at as competing choices. A story: I once had a class that met twice a week for 90 minutes and was a true seminar (10 people with a professor who had written a book, sitting around a conference table, the real deal). What we did was to read 2-3 accounts by historians of differing political slants (“schools” like revisionism, Wilsonian, etc.) of different episodes in US Foreign Policy (e.g. Open Door). For each class we had a group discussion, debate about a select period, about the assessments, etc. For ONE of them, we would also have to have written and turned in a 2 page (at most!) comparison/contrast of the different assessments. Inevitably, the discussion was BETTER on the days when everyone had written a paper. Capisce? 🙂

Steve: Congrats. Yes, one should be as careful about reports in support as reports in opposition. But you should be heartened that 3 studhorse statisticians broadly back up your criticisms of MBH work and of the softer policy issues (Mann’s resistance to examination, etc.) Take some joy in the day. It is a victory.

TCO, I appreciate your point. There are also far too many poorly written studies looking for publication. However, in some cases I do think there is a problem in getting some work published simply because it is difficult to get it beyond a cohort of hostile reviewers.

The un-peer reviewed report commissioned by Rep. Barton released today adds nothing new to the scientific discourse on climate change and is a poor attempt to further personalize and politicize what should be a matter of scientific debate not politics.

The impartial and independent National Academy of Sciences convened a panel of experts in climate science and statistics and performed a far more extensive review of the science, confirming the key conclusions of our earlier work, as well as numerous more recent supporting studies. Namely that late 20th century warmth is likely anomalous in the context of the past 1000 years and cannot be explained
by natural variability. The scientific evidence for human influence on current climate comes from a large body of independent lines of evidence of which paleoclimate data is but a small part.

Barton’s report, written by statisticians with no apparent background at all in the relevant areas, simply uncritically parrots claims by two Canadians (an economist and an oil industry consultant) that have already been refuted by several papers in the peer-reviewed literature inexplicably neglected by Barton’s “panel”. These claims were specifically dismissed by the National Academy in their report just weeks ago. Barton’s report also reveals that his panel collaborated closely with the two Canadians, yet made no attempt to contact me or my collaborators at any point.

The panel makes the odd claim that there is “too much reliance on peer-review” which goes against every principle of current scientific practice. Barton in his “factsheet’ goes further and suggests that the anonymous peer reviewers themselves are in some way biased, a claim that he cannot possibly support since peer reviewers are in fact anonymous and this was not studied in the report.

Climate science, like many multidisciplinary fields, requires broad collaboration with researchers across many areas. Any well published scientist would show a wide-ranging pattern of connection with other researchers in the field. While I am flattered that the committee seems to think that I am at the center of the field, the same analysis would have shown a very similar pattern for any researcher engaged in widespread interdisciplinary research.

My colleagues and I continue to work on reducing the uncertainties in past climate reconstructions and understanding the mechanisms of past and current climate change. Policy-makers should more constructively focus their attention on the consensus findings on climate change as presented by the Intergovernmental Panel on Climate Change (IPCC) and the National Academies of all G8 countries, rather than on pursuing politically-motivated attacks against individual scientists.

His comment shows a total mistunderstanding of social network theory. No, Mann: all networks and researchers are NOT the same. You are distinguished. The other thing to note in his response is that it is all ad him (not peer reviewed, lack background, etc.). There is not debate or disagreement or pointing out of errors on individual facts and analyses. I’m not sure if this is because that is all he has to debate with or because that is how his mind thinks (Herrdoktorprofessor mindset that your position shows the worth of your argument.)

Sigh! Well, we expected it, but it’s dishearting to see such prevarication and special pleading (not to mention the Ad Hom attacks).

I don’t know for sure how well regarded the particular statiticians on this ad-hoc committee are, but if they’re well regarded in their community, this dissing by Mann may well backfire as it will stir up another group against him. And climate reconstruction is, despite its press coverage, a small bywater in the world of science.

“Barton in his “factsheet’ goes further and suggests that the anonymous peer reviewers themselves are in some way biased, a claim that he cannot possibly support since peer reviewers are in fact anonymous and this was not studied in the report…”

BUT…

“…While I am flattered that the committee seems to think that I am at the center of the field, the same analysis would have shown a very similar pattern for any researcher engaged in widespread interdisciplinary research.”

–interdisciplinary research as defined by Mann’s idea of what that is!!!!!

The comments by Wegman on consulting with statisticians are interesting. It fits right into Hotelling’s classic discussion of the role of a Statistics Department (third mission is to consult with applied workers). Stoat can portray this in a sense of territorialism or the like, but really the other field’s are much better off to include statisticians. these things are tricky and it is easy to screw up even in much less complicated situations then climate reconstruction.

“…While I am flattered that the committee seems to think that I am at the center of the field, the same analysis would have shown a very similar pattern for any researcher engaged in widespread interdisciplinary research.”

–interdisciplinary research as defined by Mann’s idea of what that is!!!!!

As mentioned in our introduction, much of the discussion on the “hockey stick’ issue has taken place on competing web blogs. Our committee believes that web blogs are not an appropriate way to conduct science and thus the blogs give
credence to the fact that these global warming issues are have migrated from the realm of rational scientific discourse. Unfortunately, the factions involved have become highly and passionately polarized.

I finished my first reading of this report and find it has put most of the arguments that I have seen from Steve M on this blog into a well organized and clear form. This finding indicates to me that a blog can provide a wealth of information from which one can learn. That the factions on blogs can be passionately polarized is not in doubt, but if one can separate and tolerate the more passionate side of the debate (and in some cases be entertained by it) one can learn not only from the technical discussions but get a view of how the debate is being battled by interested citizens (which is not available from reading scientific papers). I do not see science being conducted on this blog (even though science could be conducted online in some form) in the true sense, but we can attempt here to understand better that science that is being conducted elsewhere.

My libertarian eye was struck by Recommendations 3 and 4 which could, in effect, be easily construed as a pleading for some government money for the statistical community even though I agree in general terms that studies often could benefit from having statisticians involved. It worked for me in my experiences in the private world of R&D.

Recommendation 3. With clinical trials for drugs and devices to be approved for human use by the FDA, review and consultation with statisticians is expected. Indeed, it is
standard practice to include statisticians in the application-for-approval process. We judge this to be a good policy when public health and also when substantial amounts of monies are involved, for example, when there are major policy decisions to be made
based on statistical assessments. In such cases, evaluation by statisticians should be standard practice. This evaluation phase should be a mandatory part of all grant applications and funded accordingly.

Recommendation 4. Emphasis should be placed on the Federal funding of research
related to fundamental understanding of the mechanisms of climate change. Funding
should focus on interdisciplinary teams and avoid narrowly focused discipline research.

And this one is for you, TCO:

9. Based on discussion in Mann et al. (2005) and Dr. Mann’s response to the letters from the Chairman Barton and Chairman Whitfield, there seems to be at least some confusion on the meaning of R2. R2 is usually called the coefficient of
determination and in standard analysis of variance; it is computed as 1 — (SSE/SST). SSE is the sum of squared errors due to lack of fit (of the regression or paleoclimate reconstruction) while SST is the total sum of squares about the mean. If the fit is perfect the SSE would be zero and R2 would be one. Conversely, if the fit of the reconstruction is no better than taking the mean value, then SSE/SST is one and the R2 is 0. On the other hand, the Pearson product moment correlation, r, measures association rather than lack of fit. In the case of
simple linear regression, R2 = r2. However, in the climate reconstruction scenario, they are not the same thing. In fact, what is called àÅ½àⰠin MBH98 is very close what we have called R2.

I think the friends of Mann are going to see the paper’s attempt to statistically document the networking involved in and lack of independence in the HS papers as a form of high tech McCarthyism.

35. Glad to see the comments from Wegman clarifying definitions. I think there are so, so, so many problems in science and work where these kinds of clarifications may be needed. In this case, we even have very senior high level guys using terms differently. This is what I liked so much about the Huybers comment on MM and why that paper is better than Steve in terms of understanding the difference between Mannian methods, correlation matrices, and covariance matrices. Sometimes clarifying a very “basic” point may be in order. yes, even for studs like Steve and Mike Mann and BC.

“As mentioned before, Michael Mann is his own group since he is a co-author with each of the other 42. The cliques are very clear in this layout. In addition to the Mann-Rutherford-Jones-Osborn-Briffa-Bradley-Hughes clique there are several others that are readily apparent. They are Rind-Shindell-Schmidt-Miller, Cook-D’Arrigo-Jacoby-Wilson, Folland-Vellinga-Allan-Knight, Stahle-Shugart-Therrell-Druckenbrod-Cleveland, Sangoyomi-Moon-Lall-Abarbanel, and Clement-Zebiak-Cane.”

Gavin Scmidt is part of the self supporting, self perpetuating clique.
Don’t expect any fair hearing or posting from Schmidt on Real Climate

The most interesting part of this report is found in Figure 4.1. I thought that the pro-hockey stick folks had discredited the McIntyre/McKitrick analysis that produced a hockey-stick effect by pumping random data into Mann’s model. However, this report claims to have reproduce it:

We have been able to reproduce the results of McIntyre and McKitrick (2005b). While at first the McIntyre code was specific to the file structure of his computer, with his assistance we were able to run the code on our own machines and reproduce and extend some of his results. In Figure 4.1, the top panel displays PC1 simulated using the MBH98 methodology from stationary trendless red noise. The bottom panel displays the MBH98 Northern Hemisphere temperature index reconstruction.

Barton’s report, written by statisticians with no apparent background at all in the relevant areas, simply uncritically parrots claims by two Canadians (an economist and an oil industry consultant) that have already been refuted by several papers in the peer-reviewed literature inexplicably neglected by Barton’s “panel”.

Actually, the report does cite W&A (2006), and notes their misrepresentation of MM’s work as an “alternative reconstruction”.

Barton’s report also reveals that his panel collaborated closely with the two Canadians, yet made no attempt to contact me or my collaborators at any point.

Mann has an amazing way of finding non-existent patterns in data. The panel did not “collaborate” with us, I only heard of Wegman’s involvement through an article a while ago in the WSJ and only today did I learn that there were 3 people on it.

The way the Mannians run RealClimate and Mann’s comments today says it all. As the saying goes “They can fool some of us all the time and all of us some of the time but they cant fool all of us all of the time.” I need to look at the spectacles Mann used to read the NAS report.

simply uncritically parrots claims by two Canadians (an economist and an oil industry consultant) that have already been refuted by several papers in the peer-reviewed literature inexplicably neglected by Barton’s “panel”

Yet the NAS panel report, which Mann uses to bolster his claims of being correct, also “uncritically parrots claims” by the “two Canadians” (how in the world is this relevant?!?!? is this like “the South Park Movie” where the US is at war with Canada?!?!?), a fact which Mann “inexplicably neglects” to mention time-and-time again.

Mann isn’t a human resources manager – how could he be qualified to identify someone an “oil industry consultant?” Mann also doesn’t have a background in geography, so I don’t know if I can believe his allegations that M&M are Canadians. Gavin et al is “tired” of this – is he a sleep specialist? I wonder if he can help with my apnea issues.

A while ago he accused Richard Muller of not simply “parroting” but “scurrilously parroting” our claims.

BTW, Wegman did some work in the 70s on either weather or climate. I warrent that he (while not a GRL afficianado) is a bit aware of the field. I haven’t seen the backgrounds for the others, but would not be surprised if they also have some weather publications in their long CVs.

With reference to Dr Mann’s dismissive reply to a careful report composed of real statisticians (of which he is not one, having said so to the NAS Panel), I’ll bring up just one misrepresentation out of the many: What Wegman et al actually said was

"In this case we judge that there was too much reliance on peer review, which was not necessarily independent"

So far from complaining about too much reliance on peer review, Wegman was pointing out that the peer review was done between a small coterie of the author’s friends who had also staked their scientific reputations on similar results in studies that had lots of the same non-independent proxies.

Long time lurker here. I was doing some more reading and I didn’t realize, but Dr. Wegman is the chair of the NAS panel on Applied Statistics. That is some pretty serious credentials calling Dr. Mann out for his statistical skills, or lack thereof.

Congratulations! That is one beautiful report IMHO, better than NAS. You should not be afraid of it. I enjoyed the part about the social network. I disagree about their statement on blogs, but as you know, I’d like to know your own opinion on this, so I’ll keep my comments to myself for now!

Prediction: Michael Mann will become more and more isolated as a researcher. But given the way he’s acted and continues to act, I don’t sympathize at all.

Congratulations Steve on a long hard job done well. There is now strong support for many of your key arguments. You made strong arguments in the past, but this concurrence from well qualified statisticians from outside both your and Mann’s social network adds enormously to the credibility of your arguments. As fFreddy pointed out, Wegman’s resume is impressive. Although on the down side I see that he did once chair a meeting in Canada (nobody’s perfect). Some of us are not statistics experts (sorry only one semester) so collaboration from experts is quite important. I hope it will make the general scientific community sit up and take notice. Refuting Mann certainly doesn’t disprove AGW. It does something more important though, by revealing the failings of the process. Maybe when the process is fixed we can get the right answer and have confidence in it.

Seriously though. Wegman is speaking the language of truth seeking science. Blogs are not sufficient nor fair for criticizing Mann (and it’s not an either/or)! I mean Mann doesn’t stop publishing because of his blog!!! 🙂

While informed readers here will certainly enjoy this report (I finally ‘got’ the decentering issue), I think it is even more important for people who have not been closely following this debate. It is written in a style that even people with only a smattering of statistics can understand, and boils down years of arguments and counter-arguments into a report that’s not frightenly long. It’s clear, to the point, and for the most part, clear of weasel wording (unlike the NAS report). It’s a nice counter-point to the NAS report and since Dr. Wegman is the chair of the NAS panel on Applied Statistics, it will be pretty difficult for Mann supporters to easily dismiss him, not that they won’t try of course. They will undoubtedly circle the wagons even tighter, but in the process they will become even more isolated, which should be no surprise to anyone that has read the networking section.

Whilst I usually read in lurker mode and usually can’t stand ‘me too’ posts – having read the report I can’t keep quiet, it is simply jaw-dropping, I’m stunned it says so much, so bluntly. Mann’s response is absolutely incredible, have Real Climate no humility? (does ‘I just might have got something wrong’ and ‘I ought to think about this before putting my mouth into gear’ not occur to them?). Congratulations Steve and Ross and especially Steve with the constant high quality posts on this site because whatever the committee say about how deplorable this is that it was fought out on blogs (although who started it?), the NAS report (which I believe was codedly critical despite what the hockey team say) and now this report have made real discussion of the whole area possible in a way that it hasn’t been for over 10 years. Well done – and don’t stop now!

Re #63: “Prediction: Michael Mann will become more and more isolated as a researcher.”

Mann may be losing scientific credibility but he is simultaneously gaining martyr status amongst those that hold AGW to be an article of faith. Mann can now go on the speaking circuit commanding big fees describing the scientific McCarthyism he has been subjected to and plugging AGW. I’m not predicting Mann will take the loot but radical blogs have been hailing Mann as a latter day Galileo. The truthsayer persecuted by entrenched interests. I view Mann as The Wizard of AGW who has had his divining exposed.

“Namely that late 20th century warmth is likely anomalous in the context of the past 1000 years and cannot be explained by natural variability.”

A. Did Mann change the terminology from the NAS report? Wasn’t plausible the word of the day?

B. I understood that plausible (weaker term than “likely”) applied to their repesentation / interpretation of the last 1000 years, and “likely” referred to the last 400. But wasn’t the Hockey stick team trying to nudge coverage of the “stick” to a 2000 year interpreThe impartial and independent National Academy of Sciences convened a panel of experts in climate science and statistics and performed a far more extensive review of the science… …to which I add – “but not the statistical tools used (misused) to tation?

C. When did Mann become an expert in statistics? These guys seem to be a bit more qualified in stats than he, no?

My colleagues and I continue to work on reducing the uncertainties in past climate reconstructions and understanding the mechanisms of past and current climate

Does this translate to mean they / he will continue to work on finding ways to massage the stats so they come out in their / his favor???

Signed Sonicfrog: geology school drop-out and chronically bad speller.

Response: Hmmm… So Wegman had access to all the peer reviews and who did them for all of the relevant studies then did he? I don’t think so. He just looked at co-authorship – which is not the same thing at all. Statements about who the peer reviewers were are just speculative with no actual facts to back them up. – gavin

My response:

So Gavin, are you confirming that neither you, nor the 41 others mentioned in the “mutual admiration society” mentioned by Wegman performed peer review on each others key studies that backed AGW?

Congrats on the additional vindication provided by the Wegman Report, you guys deserve a tremendous amount of credit. Thanks to your efforts, climatologists may finally get their act together and start acting like scientists instead of high school cliques.

Incidentally, the Scientific American blog (http://blog.sciam.com/index.php?cat=19&display=1) has run a series of postings on AGW these past few weeks and I’ve been doing my best to argue against their alarmism. The Wegman Report has come in very handy today.

Re#70 – Mann/RC’s explanation is that “likely,” as in IPCC terminology, is 66-90%. The NAS panel conclusion in the audio was 2:1 in agreement – 66.7% – but used the term “plausible” in the report. So Mann/RC is equating “plausible” with “likely” since 66.7% is in the 66-90% range.

Of course, I haven’t listened to all of the NAS audio, so I’m not sure exactly what they approve of in 2:1 fashion – it could be “anomalous warmth of the late 20th century,” and not what Mann said was likely – “1990s were the warmest decade, 1998 the warmest year,” which the NAS didn’t seem too confident with in the report.

Someone here might be able to clarify exactly what the NAS panel was in 2:1 agreement with.

Scientists are not deaf, dumb nor blind. Whilst most of them may agree with the so-called “consensus” (by definition), they are nevertheless scientists at heart. Blind faith is not part of their qualifications, and I don’t think they particularly like the kind of language and rhetoric he uses to defend himself. They can read the NAS report, and read it as scientists: see what’s in between the lines, and it’s pretty damning. Even more so with this report. Who, now, wants to be part of his “social network”, and be tagged as such? So what’s going to happen next time Mann submits a paper for publication? The Editor will make damn sure that he choses referees that are not related to him at all. The reviewers will think “So this is this Mann guy? I’ll make sure I make a really thorough review”. And what about conference program committees? Are they going to give him an invited talk? Not sure.

Of course, he’ll have close collaborators and friends to support him (I hope), and a cheerleading crowd. But scientific credibility? Naah.. he’s lost it all by now.

One thing though. I did a quick search just now and it shows that Both of Wegman’s co-committee members have published papers with him before. So while it doesn’t mean too much, it does mean that it’s not like they were three independent statisticians who banded together to check out MBH98-99. More likely Barton talked to Wegman who then called a couple of his friends and they decided to check things out.

“We note that according to experts at NASA’s JPL, the average ocean height is increasing by approximately 1mm per year, half of which is due to melting of polar ice and the other half due to thermal expansion. The latter fact implies that the oceans are absorbing tremendous amounts of heat, which is much more alarming because of the coupling of ocean circulation to the atmosphere.”
—
Page 66:
How central is the debate over the paleoclimate temperature record to the overall scientific consensus on global climate change (as reflected in previous reports from the academy)?

Ans. In a real sense the paleoclimate results of MBH98/99 are essentially irrelevant to the consensus on climate change. The instrumented temperature record since 1850 clearly indicates an increase in temperature. Whether this is unprecedented in the last millennium seems less clear and to what extent the natural planetary processes can mitigate the excess green-house gas release is unknown. What is more important in our view is real insight into and understanding of the processes of global warming.

Unfortunately, the HS was what has been used for the past 5 years to show “unprecedented” temperature changes. Nobody disputes climate change, Lee. The problem is saying “global warming” and then “unprecedented” and “anthropogenic” in the same paragraph/sentence without pointing out the problems with making such a connection.

Oh, and FWIW, the instrumental record that is oft used is not geographically balanced to be a true representation of global “mean” temperature. Like it or not, it needs to be corrected.

I agree that the comment about peer review is speculative, but Mann’s rebuttal comment about MM collaboration is also speculative.

Really, I think Mike needs to address the mathematical issues. Does he agree that the HS method mines? If so how much, etc. etc. Talking about people’s backgrounds will not get him anywhere. He is in danger of losing respect from even his “side” (and there should not be a such thing as a side) if he persists in personalizing things and failing to adress issues and admit errors.

“As mentioned before, Michael Mann is his own group since he is a co-author with each of the other 42. The cliques are very clear in this layout. In addition to the Mann-Rutherford-Jones-Osborn-Briffa-Bradley-Hughes clique there are several others that are readily apparent. They are Rind-Shindell-Schmidt-Miller, Cook-D’Arrigo-Jacoby-Wilson, Folland-Vellinga-Allan-Knight, Stahle-Shugart-Therrell-Druckenbrod-Cleveland, Sangoyomi-Moon-Lall-Abarbanel, and Clement-Zebiak-Cane.”

The un-peer reviewed report commissioned by Rep. Barton released today adds nothing new to the scientific discourse on climate change and is a poor attempt to further personalize and politicize what should be a matter of scientific debate not politics.

Doubly bizare.

“Un-peer reviewed” …, but in the next paragraph he cites approvingly to the un-peer-reviewed NAS report.

Barton’s report, written by statisticians with no apparent background at all in the relevant areas,

Ummmm … actually, …, Mann is the one without an adequate background in statistics, so when it comes to the statistical aspects of his work, Mann is the amateur, and Wegman et al. are the mainstream academics.

My colleagues and I continue to work on reducing the uncertainties in past climate reconstructions and understanding the mechanisms of past and current climate change.

So, …., Mann should welcome the insights of these statisticians as a way to improve the accuracy of the work in this field, right?

At the Joint Statistical Meetings in Seattle, sponsored jointly by the American Statistical Association, the International Biometric Society, the Institute of Mathematical Statistics and the Statistical Society of Canada, the program includes the following:

7 Aug 2006, 8:30AM-10:20AM: Session on Statistical and Computational Issues in Climate Research chaired by Donald B. Percival of the University of Washington, three invited papers, one of which is “Interpreting Recent Climate Change” by Francis W. Zwiers of the Canadian Centre for Climate Modelling and Analysis

7 Aug 2006, 2:00PM-3:50PM: Session on Statistical Methods in Climate Modeling and Seismology chaired by Gabriel Huerta of the University of New Mexico, three invited papers, Nychka a co-author of one of them.

8 Aug 2006, 8:30AM-10:20AM: Session on Climate, Weather, and Spatial-Temporal Models, chaired by Nychka, five papers, Nychka a co-author of two of them.

9 Aug 2006, 8:30AM-10:20AM: Late-Breaking Session #2: What is the Role of Statistics in Public Policy Debates about Climate Change?, chaired by Nychka, papers:

The Kyoto Accord, the 2001 IPCC Third Assessment Report, and the Academic Papers Underpinning Them, by Edward Wegman, George Mason University

Leaving aside my usual grave demeanor and presuming that the Wegman analysis will stand, one comment comes to mind in response to their report, which is” ‘Holy-kafuckies!’. 🙂

They said what the NAS panel should have said, and did so with all proper detachment and personal respect. What seems clear is that they were quite properly committed first to the professional standards of statistical methods, and were most concerned that these standards should be followed in a scientific publication that referenced them as central to the scientific conclusions offered. What they found was that the standards of statistical methods were not upheld and that, therefore, the science-based conclusions that had been offered in their name were insupportable.

It was also very good to see Wegman & co. point out that the science of tree-ring dendrology was itself far too incomplete to support any sort of analytical temperature reconstruction. It was further good to see the report comment on the “cryptic” way Mann et al., described their methods in their peer-reviewed articles (how did their peer-reviewers ever figure out what they did, anyway, in the course of their we-know-they-were-very-searching reviews?), and follow on with a well-qualified recommendation about archiving the methods and results that have huge monetary and social impacts. This kind of rational analysis has been sorely lacking from the public debate on climate.

In passing, the Wegman report makes me, as a scientist, ashamed of the NAS panel. They didn’t entirely drop the ball, but they disguised it with hearts and cherubs. There is just no substitute for clarity and forthright adherence to analytical standards. The NAS panel clearly did not do what the Wegman panel did, which is to put their professional standards foremost and let the chips fall where they may. Instead, they waffled.

Congratulations Steve and Ross. You have been entirely corroborated by those whose corroboration is to be most valued.

As a human, I note that a discussion of social networks that a particular individual belongs to is, by definition, an ad hominen attack.

As a scientist who has advised graduate students, it is odd to me to see people draw original conclusions regarding social science research and not cite any references regarding that research. It is odd to me that these authors did not try to place their conclusions regarding a scientific community into context. It would seem natural that the authors of this document would want to be immediately forthcoming regarding the social networks to which they belong.

As a citizen of the USA and a life-long Republican, I am confidant that the Honorable Members of our Congress pay attention to the conclusions of studies that are conducted under the auspices of the National Academy of Sciences.

As a PhD, who has studied applied mathematics, I am happy to continue to discuss the mathematics of climate in the peer-reviewed literature. Because I make a practice of avoiding disgusting pornographic comments such as those made in comment #85, I will see you there!

Stop taking advantage of Steve M being busy and John A being asleep. All you’re going to do is get the numbering on this topic thread all screwed up. (Where the heck did “Jasmine” come from all of a sudden?)

Scientists are not deaf, dumb nor blind. Whilst most of them may agree with the so-called “consensus” (by definition), they are nevertheless scientists at heart. Blind faith is not part of their qualifications, and I don’t think they particularly like the kind of language and rhetoric he uses to defend himself. They can read the NAS report, and read it as scientists: see what’s in between the lines, and it’s pretty damning. Even more so with this report. Who, now, wants to be part of his “social network”, and be tagged as such? So what’s going to happen next time Mann submits a paper for publication? The Editor will make damn sure that he choses referees that are not related to him at all. The reviewers will think “So this is this Mann guy? I’ll make sure I make a really thorough review”. And what about conference program committees? Are they going to give him an invited talk? Not sure.

Of course, he’ll have close collaborators and friends to support him (I hope), and a cheerleading crowd. But scientific credibility? Naah.. he’s lost it all by now.

I think you are on to something here. We may be near a tipping point here where climate scientists become seriously concerned about being tagged as dishonest for continuing to whitewash the obviously serious problems in Mann’s work. Mann’s tactics may be able to fool non-technical cheerleaders, but real scientists understand the problems the NAS report and the Wegman report have highlighted and hewing to Mann’s party line is starting to become risky — something academics do not like.

It is quite sad too. A couple of years ago, some carefully crafted language from Mann that his work was less than perfect and there was room for improvement could have somewhat graciously headed all of this off. Christy and Spencer have been paragons of this, much to their credit.

#96 -“As a human, I note that a discussion of social networks that a particular individual belongs to is, by definition, an ad hominen attack.”

Not when the network is made to test whether there is a closed conviviality in what should be an open discussion.

Your next comment imposes a subjective political cast on what should be a discussion of objective merits. It matters not a whit to what social networks the Wegman group belongs. What matters is whether their points withstand analytical scrutiny. I am so tired of various climate proponents, with those supposing AGW most especially guilty, making subjective ad hominem innuendoes about the authors of works that should be assessed on the basis of objective standards.

With regard to your proffessional standing as a PhD who understands applied mathematics and your personal position of happiness with regard to, “discuss[ing] the mathematics of climate in the peer-reviewed literature,” can we presume you have read MBH98, 99 and understood the methodological narratives that the Wegman group described as “cryptic”? If so, did you consider them clear, and Wegman, et al. merely inept? Or did you, too, find them cryptic? If the latter, then how could the confusion resulting from obscurantism be called a “discuss[ion]”?

#76
If you want to say Mann’s work is “essentially irrelevant” to the question you want answered that’s fine. Be clear though that the question of AGW warming has never been the primary question for Steve on this site. This site would attract no attention if Mann said “the study had mistakes and here is what we learned from them”. That is all it would take. But instead Mann has insisted on a take no prisoners approach, trashing Steve (called him a Canadian!) and anyone else that disagrees in the harshest terms, never admitting any possibility of error. Steve persevered not because Mann got an answer he did not like, but rather Steve did not like the way Mann got the answer. You are concerned about the answer, this site is about the method.

The question for you is whether it helps the consensus view to support a bad methodology just because it agrees with the consensus. Or would it be better to get a good methodology that gives an answer that everyone can trust? If the study really is irrelevant to the question you are concerned about, you should have no trouble joining Steve and Ross in calling for better methodology from Mann.

Over on RC, Gavin apparently thinks that reports need to be “original” (“There is nothing original in the Wegman report except the neat, but basically meangingless, social network stuff …”) in order to avoid summary dismissal. I submitted a post asking whether perhaps *correctness* wasn’t the more important aspect; we’ll see if Gavin lets it see the light.

It’s only TCO (and the occasional troll) that are bizarre. I’m afraid TCO’s a former sailor, so he’s got a mouth like one, and apparently drinks like a fish, too. Ignore him and he’ll go back to pestering Steve about obfuscating the PC1 issue.

Interesting but not hugely suprising, at least to those of us with good knowledge of the subject. I have to say that I am disappointed that the Wegman report has not received much media attention. Is it early days or are Reuters, AP and others likely to ignore it because it doesn’t support their prejudices?

John A’s comments got through at RC. I’m still waiting for mine to show up, so in case it gets lost over the weekend, here it is:

This may be off-topic for this post, but not for this website. Mann’s comments above are disingenuous. It’s with rose-colored glasses that he could claim that the NAS report confirmed the key conclusions of his earlier work. The phrases “lower our confidence” and “even less confidence” come to mind (pg 4).

Further, the statisticians who wrote the Barton report clearly have a background in the relevant area, namely statistics. That Mann fails to comprehend that his earlier work is largely a statistical exercise is baffling. (“The process of reconstructing climate records from most proxy data is essentially a statistical one…”, NAS report, pg 79)

Finally, the NAS report simply did not dismiss the claims of McIntyre and McKitrick (the topics of spurious trends, robustness, proxy selection, validation, and data archiving come to mind). I’m sorry, Gavin, if this bores you, but it truly is important to both climate change and science in general.

Mann’s rebuttal comment about “collaboration” between MM and Wegman et al was not speculative. [But it leaves open to the reader how much “collaboration” occurred…] The report states that Wegman contacted Steve M. to translate his computer program into a format Wegman could use on his computer.

“We have been able to reproduce the results of McIntyre and McKitrick (2005b). While at
first the McIntyre code was specific to the file structure of his computer, with his
assistance we were able to run the code on our own machines and reproduce and extend
some of his results.” [page 29 of report]

This struck me as unfortunate when I read the report earlier, from a public relations standpoint. An academic courtesy can provide great fodder for conspiracy theorists.

“Having read the recent NAS report and the new Wegman report, I am surprised at some of the comments here. In scientific study, one part is clearly physical (growth rates of trees, IR absorption, etc.) and a separate part is the statistical treatment of the data.

Dr. Wegman’s analysis is only of the latter (aside from some sociological mildly interesting analysis of the network of investigators, which in and of itself says nothing about the importance or handling of the data). He is well qualified to analyze statistical methods, as chair of the National Academy of Sciences’ (NAS) Committee on Applied and Theoretical Statistics, and a board member of the American Statistical Association.

The conclusion of the Committee headed by Dr. Wegman is clear – the statistical methods of MBH 98/99 cannot be relied upon to support the claim that the 90’s were the hottest decade of the past millennium. If one wants to argue with Dr. Wegman’s conclusion, it will be necessary to show how he has misunderstood or misrepresented the statistical methods used in those studies.

This conclusion does not “prove” that the Medieval Warm Period was warmer than the present, it does not “prove” that CO2 is not causing warming, it does not “prove” that all climate science of the past decades is rubbish. However, if one wants to argue against any of these points, unless one can show reasons why the Wegman Committee analysis of the statistical methods of MBH 98/99 is incorrect, the obvious scientific approach would be to accept that MBH 98/99 cannot be the evidence to support such argument.

Anyone with an interest in climate in general and paleoclimatology in particular should read the NAS report and the Wegman Committee report.

Hi all
A great day for truth and honestey. Well done Steve (mainly I think) and Ross.
I hope the Kyoto freaks in the New Zealand government take heed on what they are doing.
Regards
from New Zealand
Peter Bickle

85 95 116 and 91 I think Jasmine might have been offended by 91 instead of 85 unless she is referring to a post has been deleted. (I still haven’t figured out why my first post from 7/14 was deleted). I don”t think 91 passes the Principal Component test.

Ok, good point about the computer change. I guess Mann has the grain of a point on that issue. Like Wegman should have asked for the Mann data/code that he wanted also. Probably did and didn’t get it. And if he didn’t, then we know the likely fate if he had. But if he didn’t, Mann can still kvetch on that.

Still hilarious how Mann has no response on the actual science/math. And how he thinks Wegman (NAS Applied Stats chairman) unqualified to assess his MBH98 meta-analysis (a statistical construct).

It is so transparent how Mann’s and Gavin’s comments thus far sound the way they do. You think they would defend the methods or the math, or at least show some outrage if the report misrepresented something completely wrong. Instead they direct every one to read what the IPCC says or other topics “already discussed” on Real Climate, and then act bored with the whole thing.

What I am seeing is no respect for this report, no respect for other scientist not in their clique, and no respect for the people who actually run this country and represent it’s citizens.

I see no respect for the citizens who work and pay taxes to support policy action and research, and should always demand that the top scientists “in the news” and at the forfront of important issues to at least be honest ones.

No respect for parents who have children who are taught in school that the Hockey Stick proves GW is man made.

Let me give what I’ve absorbed on this issue and people can correct what I’ve gotten wrong.

The ultimate trouble is that trees don’t produce rings of uniform size, even if the external situation remains unchanged. They gradually produce more narrow rings as they get older. Partially this is simply the change in surface to volume ratio (productivity is a function of surface area while rings have an increasing volume at the tree gets older So if you want to be able to look a the climate, an adjustment must be made to each tree’s ring width’s to compensate for its age. Of course this is only going to be approximately accurate and there will remain some problems with any given tree. But assuming we sample a number of trees in any area the differences should largely average out. Still, there may be problems, especially in the lower frequency data.

I think this is a bit different than the problem which there’s an attempt to correct in the article Jean S is looking for, however. It seems to be concerned with differences caused by varying stand densities over time. But I don’t have access to it either so I don’t know for sure.

The NAS concluded that Mann had an undocumented, never before used method of “off-centering his PCA. THat this method mines for hockey sticks. They BACKED up this conclcusion of Steve’s. WEgman found the same thing. Mike has never addressed this particular issue. Why is the off-centering there? Was it a mistake. We’ve heard the misdierction (it doesn’t matter, other studies show same thing, etc.), but never a direct addressal of this problem. So, Mike, WHY is that in the code and WHY didn’t you report it in the article?

Back on the science for a second, figure 4.7 is very interesting. Wegman shows something about the GENERAL mining properties of the transform that Mann does. And note, this has nothing to do with the source of the data (if it is good or bad). Has to do with the shape. Hmmm….I wonder who advocated this sort of investigation. Was it…SATAN!? [/churchlady]

You see, TCO, once you put something into the record, it is available for anyone to use in the future. That is the method by which science advances. So it’s not hidden in the Wegman report that he verified Steve’s finding on the consequences of using off-center PCA. He even did what Steve attempted to do with Mann and get Steve to show him how to make his code work on his (Wegman’s) computer. This finding has been verified several times now and really can’t be argued. Off-center PCA using a rising calibration period will preferentially select hockey sticks from reddish proxies or pseudoproxies.

So, moving on, can the other multi-proxy studies do what MBH98-9 can’t? Steve’s given many indications that they can’t. But the indications need to be published in the relevant literature, as you say. After the hearing coming up, I suspect that that is what’s next on Steve’s plate.

One thing Wegman comes down on very hard, if you think about it, is the disdain he holds for those who are withholding data and methods. Steve, the NAS Panel, Wegman and very likely the US House subcommittee are all going to unite on this one point. Come on, Jones and all you others who are holding out. Release the data or admit you’ve lost it and give explicit permission for anyone who happens to have a random copy to release it. And you Journal Editors, make it “perfectly clear” that if you don’t have the data and won’t post it, you can’t use it in any future paper.

Re #129 and #130 – When you look at the list of papers and talks Dr. Wegman has done, there are several on “data mining”. I have not read them, but he may give his view of “data mining” there. That was part of my joke in comment 14 in the other thread.

Re:#126
TCO your complaints can be a bit misleading whether you are picking on Steve M or Mike M:

You said in #126:

The NAS concluded that Mann had an undocumented, never before used method of “off-centering his PCA. THat this method mines for hockey sticks. They BACKED up this conclcusion of Steve’s. WEgman found the same thing. Mike has never addressed this particular issue. Why is the off-centering there? Was it a mistake. We’ve heard the misdierction (it doesn’t matter, other studies show same thing, etc.), but never a direct addressal of this problem. So, Mike, WHY is that in the code and WHY didn’t you report it in the article?

The Wegman report indicates that the MBH98 reported reasons for using the calibration period that they did is reasonable — for those not versed in statistics:

In general, we found MBH98 and MBH99 to be somewhat obscure and incomplete and the criticisms of MM03/05a/05b to be valid and compelling. We also comment that they were attempting to draw attention to the discrepancies in MBH98 and MBH99, and not to
do paleoclimatic temperature reconstruction. Normally, one would try to select a calibration dataset that is representative of the entire dataset. The 1902-1995 data is not fully appropriate for calibration and leads to a misuse in principal component analysis.
However, the reasons for setting 1902-1995 as the calibration point presented in the narrative of MBH98 sounds reasonable, and the error may be easily overlooked by someone not trained in statistical methodology. We note that there is no evidence that Dr.
Mann or any of the other authors in paleoclimatology studies have had significant interactions with mainstream statisticians.

The calibration period and the off-centering are two different issues, Ken. Also Mann never stated in the paper that the PCA was off-centered nor has he ever said why it was done or if on purpose or not.

Note: Although the House Committee on Science initiated the Academy study, the Academy decided not to address the specific questions of the House Committee on Science and decided to focus of the Academy study away from the specific questions and address broader issues. Page 64

No I don’t remember chiding you. I distinctly remember being unimpressed that the NAS Panel widened the scope of their inquiry to generalities and did not focus on the specific questions asked by the people who had commissioned them (Boehlert’s Committee)

Oh…btw, your graph looks pretty juvinile and btw, Wegman is not indicting Mann BECAUSE of his connections. He blows apart the stats (and backs Steve up). He has the stats cred to do so and the general science cred to comment on things like Mann’s improper, opaque and flawed description of methods, of wrongness of refusing to share data and methods when asked, etc. When he does the social network, it’s in ADDITION to the stats body blow. It’s EXPLORATORY.

The point is GIVEN that Mann is wrong, why didn’t people catch him. The Von Storch comments about the chilling impact of anyone who disagreed with the conventional wisdom are interesting here. Even if Steve is on the take from the Marshall Institute (and I see no evidence of that given how rinky dink the site is, tech-wise), it doesn’t matter if his STAT ARGUMENTS ARE RIGHT.

save from CT: A. The post seems to say that Wegman thinks it notable that the Mann co-author group all contains coauthorship with him. If you read the report, it is clear that Wegman’s remarks are explanatory of a general feature of the network: are not meant to be showing some special discovery. More like explaining why you have a row of ones down the diagonal of a comparison matrix. This reminds me of the people who cackled on this site about Ross not knowing the difference between radians and degrees when the error was clearly one of input (that he did not know that the program needed him to convert conventional lattitude to radians before inputting). I think everyone knows that degrees and radians are different. They also know that a network selected to be coauthors, will all be coauthors! Sheesh.

B. Some examples: “as mentioned before, Mann is his own group since he has co-authored with all of the 42”, “The first database is Mann-centric with the idea of investigating relationships among his closest associates”. (There are a couple others, but I’m too lazy to retype from a pdf.) Anyhoo…it’s clear that this guy who has published networks is being explanatory to a general audience of a feature. Not citing a discovery.

Congratulations to Steve and Ross. What a triumph. Mann’s position is as always, ignore the issues and attack the source. He need never respond to the arguments and he never will. But there is a good measure of success in the offing, namely whether or not the IPCC uses the HS in the next assessment. Time will tell.

As for the science, Wegman is very important, as are M&M. There is a lot of evidence for a MWP, including written evidence. If one doesn’t know that they don’t understand the situation. There is also evidence against it. So the state of the science is that the case is unclear, just as Wegman says. Unclear means we don’t know, just as I have always said.

As Wegman points out, the other proxy studies are like buying additional copies of the same newspaper to verify the truth of the first copy. It follows that we do not know that the present warming is unusual. Period. That’s it. That’s the science. We don’t know. (A normal condition in science research.)

The “do not know” part is certain for now. So any and every argument based on the idea that the present warming is unprecedented, or even unusual, is invalid. Not because the premise is false, but because it is not known to be true.

I agree that the social network is the novel thing about the report. It is NOT the only noteworthy thing about the report. What you have also is

A. A very, very good statistician (better then either Mann or McIntyre) looking at the Mann work, the McI critique and finding for McI. (One has to wonder, do you find any flaw with that part of the report? Did you already agree with McI about how the off-centering mines for hockey sticks? Did the rest of the field agree?
B. That same experienced statistician saying that Mann’s descriptions of method were vague and opaque in his papers, that he used non-quantitative language to describe his method’s skill, and that the data and code was insufficient to allow verification.
C. Some minor things (some new, some repeats) like that Mann confuses r and R.
D. Also new: that the method will mine for shapes IN GENERAL from white noise. Not just hockey sticks. But any low freq sample with white noise will be magnified. See Fig 4.7. (This actually interesting from purely intellectual stance.) That the Mannian method will extract a shape from 1 out of 70 noise samples, whereas conventional PCA would give a noise-looking PC1.
E. That Mann’s method can not be technically PCA (because of the transform when he offcenters). It’s not actually a PRINCIPLE component.

I would be interested in how this compares with other fields/networks. Obviously Wegman did not address this, but perhaps you, who have seen a lot of networks, can. My impression from work (not a network study) is that this is a very different sort of field from solid state chemistry for instance. In terms of the amount of interconnections and the groupings.

The calibration period and the off-centering are two different issues, Ken. Also Mann never stated in the paper that the PCA was off-centered nor has he ever said why it was done or if on purpose or not.

The Wegman paper says with my emphasis italicized the following:

The key issue in dispute is the CFR methodology as used in MBH98 and MBH99. The description of the work in MBH98 is both somewhat obscure and as others have noted incomplete. The essence of the discussion is as follows. Principal component methods are normally structured so that each of the data time series (proxy data series) are centered on their respective means and appropriately scaled. The first principal component attempts to discover the composite series that explains the maximum amount of variance. The second principal component is another composite series that is uncorrelated with the first and that seeks to explain as much of the remaining variance as possible. The third, fourth and so on follow in a similar way. In MBH98/99 the authors make a simple seemingly innocuous and somewhat obscure calibration assumption. Because the instrumental temperature records are only available for a limited window, they use instrumental temperature data from 1902-1995 to calibrate the proxy data set. This would seem reasonable except for the fact that temperatures were rising during this period. So that centering on this period has the effect of making the mean value for any proxy series exhibiting the same increasing trend to be decentered low. Because the proxy series exhibiting the rising trend are decentered, their calculated variance will be larger than their normal variance when calculated based on centered data, and hence they will tend to be selected preferentially as the first principal component. (In fact the effect of this can clearly be seen RPC no. 1 in Figure 5 in MBH98.). Thus, in effect, any proxy series that exhibits a rising trend in the calibration period will be preferentially added to the first principal component.

See also from Wegman:

Two principal methods for temperature reconstructions have been used; CFR4 (climate field construction) and CPS (climate-plus-scale). The CFR is essentially a principal component analysis and the CPS is a simple averaging of climate proxies, which are then scaled to actual temperature records. The controversy of Mann’s methods lies in that the proxies are centered on the mean of the period 1902-1995, rather than on the whole time period. This mean is, thus, actually decentered low, which will cause it to exhibit a larger variance, giving it preference for being selected as the first principal component. The net effect of this decentering using the proxy data in MBH98 and MBH99 is to produce a “hockey stick” shape. Centering the mean is a critical factor in using the principal component methodology properly.

Our Man In Puerto Rico rightly admonishes your bending author for failing to give sufficient credit to the lone scholar, the late John Daly. He was the first to attack the hockey stick theory with hard evidence and he identified the existence of the coterie. It would be too much to hope that the victory of one honest amateur scientist over million-dollar teams of shysters would ever be acknowledged by the scientific establishment, but let some of us remember.

Ken, you are still confused. I know how you were confused. I knew it before. Let me teach you:

calibration period issue: has to do with the trend inside the data and how valid proxies are judged to be based on accordance and the danger that this does not tell much given possibility of autocorrelation.

Off-centering: has to do with a transform used before putting data into the matrices of the PCA.

Definition
Data mining can be defined as “the nontrivial extraction of implicit, previously unknown, and potentially useful information from data” [1] and “the science of extracting useful information from large data sets or databases” [2]. Although it is usually used in relation to analysis of data, data mining, like artificial intelligence, is an umbrella term and is used with varied meaning in a wide range of contexts. It is usually associated with a business or other organization’s need to identify trends.

Data mining involves the process of analysing data to show patterns or relationships; sorting through large amounts of data; and picking out pieces of relative information or patterns that occur e.g., picking out statistical information from some data.

calibration period issue: has to do with the trend inside the data and how valid proxies are judged to be based on accordance and the danger that this does not tell much given possibility of autocorrelation.

Off-centering: has to do with a transform used before putting data into the matrices of the PCA

It’s ok, old man. But you are WRONG!

You do not get to be an old man without being wrong on occasion and there’s nothing wrong with that, particularly when you learn from those mistakes.

Just to make sure we are talking about the same things here, I must ask if you agree that when Wegman talks about the calibration period that you refer to above it is the period from 1902 to 1995 and when he talks about off-centering it has the same meaning as you used in your initial question asked of M. Mann and as you used it above and the average for PCA was taken from the calibration period of 1902 to 1995 when it properly should have been taken from the entire period for which the PCA was applied.

Would you also agree that M. Mann naively uses this period because it was covered with actual instrumental data and to the laymen this would seem reasonable as it would appear to be more accurate.

Also, is it not obvious that M. Mann is not qualified to use/select these statistical methods as the Wegman report indicates (and as Steve M has demonstrated) and posing the question to him is beating a dead horse.

I don’t know why he used it. If it was a mistake or on purpose. I’m interested in knowing.

Also interested in having him admit that he did so and that it has an influence. He needs to start being a truth-facing scientist. Not a debater and a baby of a debater (look at review #2 on BC paper).

Thanks, John B, for reminding us. John Daly was the first lone warrior in the battle for common sense. Patrick Michaels has also been fighting this for a long time (the Univ of VA tried to cut his dept’s funding years ago to “encourage” him to leave, but he perservered).

Sorry if I am a Cargo Cult Scientist. Can I post again my lame attempt at simplying the issue, so that I personally can understand it? Please DO tell me where I am wrong.

1) Normalization, aka Centering.

a) Mann was not statistically abliged to normalize the data, as it was somehow in non-dimensional form (nor would he have to if it was in temperature degrees in all cases).

b) But some series were tropical and others were from northern or even arctic regions, with far different ranges. So in an effort to “Globalize” it, he had to normalize it. Then in percentage terms he is comparing apples with apples.

c) So if I have a series that ranges from 0 to 1 and another that ranges from 0 to 100 (exaggerating), after normalization the percentage changes are equal.

d) Now, even this Cargo Scientist would never dream of normalizing the data to ~~the last 8% of the data series (the 20th century) and hope to find meaningful data relationships or infomation way outside of that period. The volatility may be WAY different.

e) Paraphrasing the RC for Dummies FAQ, “We did this to examine how the data related to the known instrument record.” (To me this is some sort of weird attempt at calibration.) Then paraphrasing Wegman, “MBH couched the reasons for normalizing the data to 1902-1980 in terms that would seem reasonable to many, but was fundamentally unsound.”

2. Calibration

A different process, and not to be confused. My lame description: AFTER the PCA temp reconstruction if you are off a couple of degrees compared to the instrument record, you simply adjust your whole reconstruction accordingly.

3. Verification

Was this done? It would imply splitting up the already short instrument record and seeing if you could reproduce the other part of it, right?

Just asking if I have and approximately correct handle on the issues. Thanks.

btw, I would appreciate it if someone with more understading of the statistical issues would “frisk” the above post (#154). I’ve not had a single course in statistics and have been struggling with all this, though I still “have one or two marbles rolling around up there”

This report, and the upcoming Congressional hearings, are important stories for the public to hear. I fear that these stories will never reach the public because of the military action in Israel. Most media sources will report on the military conflict next week; when the conflict ends, they will not go back and report on the hearings because it won’t be ‘timely.’

Don’t sweat it. Mann is becoming a joke even in his own coterie. We will never get to say I told you so, because the fanboys will say that they knew it all along (re offcentering and the like). It’s ok, though. At least we crushed the hockey stick.

Thanks for reminding me of John Daly’s contribution. It was his web site that sparked my global warming skepticism, which inturn led me to Climate Audit and the other excellent blogs on this issue. May John rest well with the publication of the Wegman Report.

Joel, I am not the one to ask, but I think the Wegman report gives an excellent overview of the PCA issues. Also, as TCO suggested, look at McKitrick: “What Is the Hockey Stick Debate About?” for more on “centering” or “decentering”.

#165 Hi Pat. I have a plot brewing. How about I try to write a ‘straight’ news article on the Wegman report, and then submit it to social news sites digg and Netscape. Then, we all go in and vote for it so it gets on the front page of these sites. I feel outraged that the media are not giving people the opportunity to reflect on the information. Its possible for the internet to flex its muscles with social networking.

Well, I think the Wegman Report will get some play later when the House Subcommittee has its meeting and Dr. Wegman presents it formally. But, of course by the the MSM will have all gotten their talking points from the usual suspects and who knows how it will be spun. Still we can figure TCS and the WSJ and possible Fox News to have shows or articles touting it. It will work its way around, just not as quickly as if the MSM picked up on it. Hmmm. Think I’ll see if Free Republic has picked up the story. I don’t go there too often, but it’s interesting sometimes to see what they show.

It will be very interesting to see how the impact of the Wegman Committee Report on Dectection & Attribution (D&A) will be played out.

The TAR defines detection as follows: “Detection is the process of demonstrating that an observed change is significantly different (in a statistical sense) than can be explained by natural internal variability…”

The most recent overview of D&A I’m aware of is by a committee (which includes Drs. Hegerl, Crowley, Jones and about a dozen others) last year in the Journal of Climate. They describe the importance of temperature and proxy records as follows:

” Both instrumental measurements and proxy data can
be used to investigate climate change and climate variability
of Earth’s recent past. However, prior to the mid-nineteenth century, only European instrumental data are adequate to extend temperature time series back to about 1750. Before then it is necessary to use proxy records to estimate temperatures. Although the proxy evidence is less reliable than instrumental data (e.g., Jones et al. 2001; Esper et al. 2002), estimates for
earlier centuries (particularly the last millennium) are vital as they enable the last 140 yr to be placed in a broader context. These records also provide estimates of the range of variability on decadal to century time scales that can occur naturally because of external forcing from solar output changes and explosive volcanism, and due to the internal variability of the climate system”.

In reviewing the reconstructions they reaffirm the now famous conclusion from MBH 98/99: “The reconstructions show that the average temperature of the last decade of the twentieth century, was probably the warmest of the last millennium”.

In stressing the importance of this finding, they continue: “The warming during the twentieth century, which is approximately 0.6 K (Houghton et al. 2001), is unusual in relation to the variation of warming/cooling estimates within each century of the rest of the millennium that are obtained from paleoreconstructions. Thus, proxy-derived series suggest that twentieth century warming is unique in the last millennium for
both its mean value and probably for its rapidity of change”.

In their concluding remarks, they return to this topic one more time to say: “Paleoreconstructions of hemispheric mean temperature show that the twentieth century warming is unique in the last millennium both for its size and rapidity”.

My conclusion is that a lot of papers on D&A are going to have to be re-written (discarded?) in the wake of the Wegman Committee Report. This could account for some of the current quietude.

The Detection and Attribution sections will definitely need to be revised.

My impression is that as a result of both the NAS Panel and Wegman reports, the IPCC report will be even more shrill and dismissive, especially in the Summary for Policymakers. Having lead so many men to the top of the hill, they’re going to struggle to march them back down in retreat.

So, what would it mean, if the reconstructions indicate a larger (Esper et al., 2002; Pollack and Smerdon, 2004; Moberg et al., 2005) or smaller (Jones et al., 1998; Mann et al., 1999) temperature amplitude?
We suggest that the former situation, i.e. enhanced variability during pre-industrial times, would result in a redistribution of weight towards the role of natural factors in forcing temperature changes, thereby relatively devaluing the impact of anthropogenic emissions and affecting future predicted scenarios.

Re #169 and 170: I’m afraid your mutual desire to overturn the entirety of climate science has led you to misunderstand the significance of the HS to D+A. Did you both fail to read the AR4 draft? I see no reason to expect a substantial change in it.

I’m afraid your mutual desire to overturn the entirety of climate science has led you to misunderstand the significance of the HS to D+A. Did you both fail to read the AR4 draft? I see no reason to expect a substantial change in it.

I wrote that I don’t expect a substantial change in the AR4, except that it will be more shrill.

I’m afraid that the entirety of climate science was overturned by the HS. Climate science is slowly righting itself (but no thanks to you)

There’s a distinction between “well done” and putrified, as this two year
old information demonstrates. The error-prone amateurs McIntyre and
McKitrick were debunked long ago. See the “hockey stick” posts onhttp://www.realclimate.org for details. For those who haven’t been following this,
right-wing think tanks have continued to promote M&M in the right-wing
finanical press (e.g., the Financial Post and Wall Street Journal) far
beyond their “sell by” date. Recently, after it became clear that his
efforts were not going to result in Mann being abandoned by other climate
scientists, and indeed when Mann and his co-authors were successfully
defended by the entire scientific establishment against a Wall Street
Journal-inspired attack by Rep. Joe Barton (R-Exxon), McIntyre has gone on
the attack against the entire field of paleoclimatology. The basis for this
is McIntyre’s belief that the scientific standards used by
paleoclimatologists are not of adequate quality from the point of view of a
geologist working in the fossil fuel industry. Imagine that.

P.S. — An audit of Canadian birth records through 1930 proves that M&M
don’t even exist!

I only can add my admiration for the “amateur” John Daly, unfortunately passed away too soon, for his immediate reaction on the publication of the HS, with lots of facts all over the globe contradicting the HS graph.

Thanks to him and the Mc’s and the NAS panel and now Wegman e.a., the road is free for the Climate Science community to look at better proxies and better methods to know what really happened in the past thousand(s) years…

RE: #172, Dear Steve Bloom, perhaps I have misunderstood the significance of MBH 98/99 on D&A (for which I hope I can be forgiven since these reports or others based on them seem to appear in every D&A review). Can you eloborate on the significance of MBH 98/99 to D&A in your view?

Leaving aside your attribution to me of a motive, surely you do you not suggest that the “entirety of climate science” is based on MBH 98/99? My comment about D&A reports being re-written or discarded was merely reserving a practical judgment about whether it would be easier to re-write the D&A reports to ensure no part of them are based on statical methods which are thoroughly discredited, or to discard them and start from scratch.

Steve, my reaction on your last post on RC didn’t make it (yet). The main point about variability in the pre-industrial past is that models need to adjust their overall sensitivity or their specific sensitivity (for GHGs/aerosols), accordingly to match the 1.5 century old instrumental record (as far as that is reliable). If there was a large natural variability in the past (like Moberg, Esper,… indicate), then there is less room left for GHG/aerosol variability in current times and 2xCO2 influence will end at (or below) the lowest range of the IPCC with a benign warming. If Mann98/99 or Jones98 were right, then sensitivity to GHGs/aerosols must be high and 2xCO2 ends at the upper limits of the IPCC range, which includes disaster. This has nothing to do with denialists, see the opinion of Esper e.a. in comment #171.

About the newest aerosol/cloud connection, I downloaded the Science article, but haven’t digested it yet. Some fast comment: they suggest a 5% increase in global cloud cover from anthropogenic aerosols, which is the difference between an increase by white (sulfate) aerosols and a decrease by black (soot) aerosols. That number is pretty high. The influence should be visible in huge changes in cloud cover over North America/Europe and SE Asia, as there is not much change in global pollution, but a firm reduction in Europe/NA and a firm increase in SE Asia since 1975. The resulting increase in pollution thus should lead to an increase of clouds around the NH equator, but actually there is a decrease in cloud cover in the 20S-20N band since 1985… The only exception is over the Indian Ocean, where there is an increase in cloud cover, but equally over the highly polluted NH as over the much cleaner SH near the equator. See the work of J. Norris

Checking in briefly – my own impression of D&A studies is that they are not free-standing of HS studies (none of the latter being usable in my impression.) That’s an impression. However, there are numerous references to HS results in D&A studies and many D&A authors are also HS authors – so you cannot assume that the D&A studies are free-standing.

re #177: Additionally, reading the abstarcts and conclusions, I think even MBH98 was essentially meant as a D&A study, and the focus changed to the temperature reconstruction in MBH99.

Another point (not related to D&A) I’d like to raise is that I think the claim in MBH99 about “1998 being the warmest year in millenium” was never actually peer-reviewed: it does not appear (naturally) in the preprint (submitted Oct. 7 1998), and from the final version we find: Received October 14, 1998; revised January 21, 1999; accepted January 27, 1999. I seriously doubt that the editor sent (and received the comments back) between 21.1. and 27.1.

The original manuscript (from Conclusions):

Nonetheless, even if these uncertainties and caveats are taken into account, certain important conclusions are possible. While the early centuries of the millennium approach 20th century levels of warmth, the late 20th century still appears anomalous: the 1990s is almost certainly among the warmest few decades, if not the warmest decade this millennium. Several recent years are almost certainly among the few warmest, if not the warmest.

and the final:

Although NH reconstructions prior to about AD 1400 exhibit expanded uncertainties, several important conclusions are possible, notwithstanding certain caveats. While warmth early in the millennium approaches mean 20th century levels, the late 20th century still appears anomalous: the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium.

Also, notwithstanding 🙂 English is not my native language, the original one actually seems to be bolder in their claims, which puts Mann’s comment (from RC/NAS post) to a different light (emphasis mine):

The authors of the report accurately report the considerable uncertainties that were acknowledged by seminal earlier studies. In particular, Mann et al 1999, which was entitled (emphasis added) “Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations, emphasized the uncertainties and caveats, particularly with regard to reconstructing large-scale surface temperature patterns prior to about AD 1600

So regarding these now complete rebutted (I start liking the word) 1990’s claims, the uncertainties were (slightly) emphasized likely by the request of the reviewer(s). Notice also the AD1400 –> AD1600 change in the RC comment 🙂

I am actually delighted to see that Mann has resorted to his normal tactics of playing the man, not the ball:

Barton’s report, written by statisticians with no apparent background at all in the relevant areas, simply uncritically parrots claims by two Canadians (an economist and an oil industry consultant) that have already been refuted by several papers in the peer-reviewed literature inexplicably neglected by Barton’s “panel”.

Mann has gotten away with his vitriol expressed against M&M. However, when he chooses to smear statisticians, who appear to be at the center of the US statistical community, I can imagine that there may be a substantial, and thoroughly edifying, reply. 🙂

I’m glad Tom Maguire at Just One Minute picked this up. He has medium level traffic and gets checked out by all the big blogs like Powerline and Michell Malkin. Even by some of the lefty ones. I hate to bring the hoi palloi in, but getting this freeped would probably not hurt. They took down Rather after all…

uh oh… just checked my email and thought I better clear up any confusion I might have generated.

Jasmine is not my name… I’m not foolish enough to put scientific matters up for discussion in an environment that is not peer-reviewed. The stakes (academic integrity) are too high.

So to answer the email:
I’m not Dr. Said! I earned my PhD in 1994 and not 2005.

1. Not at all. Nor did I find the paper confusing. Finally, I don’t have any trouble implementing my own code. In using someone else’s code, it would be trivial to replace machine-specific directory structures.

2. My own experience with the peer review system suggests that it is surprisingly independent. I can not imagine how the authors drew another conclusion unless they were reviewers or editors for those papers. Incidentally, I’m quite sure there are more "climate scientists" than those who have published on "temperature reconstruction" and so the entire discussion of "cliques" is ludicrous.

3. What reaction? I must have missed it.

4. I’m going to make a wild speculation and guess that Yasmin, a recent PhD and a lecturer, was merely still working with his advisor. Unfortunately for him, it was bad advice.

Oh and Jasmine “girl”, if you think that new stats methods should be made by drop-outs from physics in little backwater places like paleoclimatology and never be checked by the real mathematicians, you’re pretty stupid.

Have Bradley or Hughes commented? While Mann is correctly the focus and Wegman correctly identifies him as the common demoninator in the group publications and mentality his coauthors must realize their reputations are also in jeopardy. Something about aiding and abetting seems relevant here! It is clear there are levels of commitment to Mann in the group with Schmidt as a close and vehement defender. However, there are others who have taken positions at varying distances. What are people like Trenberth, Schneider and especially Wigley saying or thinking? All those asociated with the TAR4 and especially the Summary for Policy Makers (SPM) who grabbed at Mann’s work as the ‘smoking gun’ of human cause of warming must have positions, but as far as I can tell they are very quiet. Of course, it could be because the media haven’t or don’t want to realize the implications.

re #188: Jasmine, what a strange comment you made ‘I’m not foolish enough to put scientific matters up for discussion in an environment that is not peer-reviewed. The stakes (academic integrity) are too high.’

I submit that one of the key requirements of science is to engage with the public. It has been one of the very great failures of late 20th century and now 21st century science not to involve the public in scientific discussion and argument. It is one of the many reasons scientists are not trusted and seen as remote and aloof. There is a very noble tradition through bodies such as the Royal Institution in the UK, and I presume similar organisations elsewhere, to present public lectures and debate. Indeed it is the tradition of a PhD defence, at least in Europe, that interested members of the public may attend. I grant this is very rarely if ever upheld!

These are not peer reviewed forums. If your comment is driven more by the fear of what colleagues and peers might think then this only serves to highlight the politicisation of science and is a situation to be deplored.

Ad hominem attacks, like those in this discussion, and in this report, are offensive and nonsensical. I’ll watch from here, thank you.

Yet you seem to be defending Michael Mann, whos only defense to date are a string of ad-hominem attacks. Good show.

And, apparently you missed the point about the comments regarding peer review. The report did not say “all of climate science has a poor peer review system.” It clearly pointed out 43 climate scientists that regularly review their own work, all of which have co-authored papers together. For something that is supposedly “surprisingly independent,” there’s an awful lot of self stroking in that mix. Furthermore, that there are “cliques” is not just apparent, it is necessary. The so-called “independent panel” of the recent NAS hearing contained more co-authors and even one of the presenter’s supervisors! Unbelievable.

#166 That sounds like a good plan, David 🙂 But to give the media their full opportunity to behave ethically, maybe it would be better to wait and see what response, if any, follows Wednesday’s congressional hearings.

The following excerpt for the link here describes what I think is generally considered the calibration period for multiproxy networks:

We first decompose the 20th century instrumental data into its dominant patterns of variability, and subsequently calibrate the individual climate proxy indicators against the time histories of these distinct patterns during their mutual interval of overlap. One can think of the instrumental patterns as ‘training’ templates against which we calibrate or ‘train’ the much longer proxy data (i.e., the ‘trainee’ data) during the shorter calibration period which they overlap. This calibration allows us to subsequently solve an ‘inverse problem’ whereby best estimates of surface temperature patterns are deduced back in time before the calibration period, from the multiproxy network alone.

It is my understanding that Mann and company selected the calibration period for both calibration, as indicated in the outlined procedure above, and for the determining the standard deviations and averages to normalize or “center/decenter” the data from the entire time period of the proxy study. He should have properly used the mean and standard deviations from the longer period and by doing what he naively did was a major factor in producing the HS shape. Is my understanding correct? If it is correct, were there any further problems noted with Mann’s use of the calibration period to simply calibrate (excluding the “decentering” problem). I ask in a selfish pursuit to learn.

Actually, it is my belief that they should have dropped PCA on tree-rings in the first place. Even if he used the proper mean, tree-rings STILL are not valid temperature proxies and this concept was mentioned in MBH98 as a must (first assumption as a matter of fact, i.e. no linear relationship means invalid proxy).

So, even with a proper mean calculation, it is still hand-waving and wiggling!

ENERGY: Wouldn’t the world be a better place if OUR Honorable Members could spend their time discussing pertient issues regarding energy self-sufficiency instead of an ad hominem attack against a junior scientist from non-citizens who are "drop-outs from physics in little backwater places?"

>Well George, I am curious. Have the skeptics made enough comments to demonstrate that theirs is a legitimate point of view, albeit one you do not accept?

>Actually I am puzzled by this whole exercise. Your title is “Are You a Global Warming Skeptic?” This suggests that you are going to present the skeptical arguments in some detail then argue against them. Or perhaps present both sides.

>But you do neither, rather you present a long, detailed argument for the theory of human warming. Skeptics are then asked to refute you arguments. This is impossible for reasons that have nothing to do with your being right. Here is the first problem.

>You present perhaps two hundred sentences. Many of these are subject to well known skeptical objections that you fail to mention. Suppose it takes three sentences to spell out the response to a single sentence of yours. Such a posting would be three times longer than your original essay. What we get instead is what we see on every blog that handles this issue. Long arguments about a few points, leaving the whole mostly untouched. It looks like you are winning but you are not.

>Second, you have left out high level skeptical arguments that offset yours. For example that the temperature dropped in the mid-century while CO2 levels went up. Or that it was just as warm 1000 years ago when CO2 levels were low. The truth is that one can frame a two hundred sentence skeptical argument that is just as compelling as yours.

>You cannot refute the skeptics, nor can they refute you. The science is a draw at this point. That is why the public, and the scientists, are so divided. Your blog, like very other blog on this topic, demonstrates this fact. Every argument has a good counter argument. Good science is like often that.

An SUV??? … That comment was ALMOST as bad as repeatedly commenting on whether I’m a woman or not.

Why ?

I haven’t defended Mann other than to say that I didn’t find his writing obscure.

He managed to be obscure enough that he fooled you. Or are you saying that you saw through his nonsense ?

Wouldn’t the world be a better place if OUR Honorable Members could spend their time discussing pertient issues regarding energy self-sufficiency instead of an ad hominem attack against a junior scientist from non-citizens who are “drop-outs from physics in little backwater places?”

Not sure what you are trying to say here. TCO’s reference to physics drop-outs referred to Michael Mann.
What did you mean by your reference to “non-citizens” ?

Joel McDade, if you have trouble reading Mannian verse,pages 9,10 and 11 of the NAS report here on “Surface Temperature Reconstructions for the Last 2,000 Years (2006)” give an excellent description of the steps in constructing a multiproxy reconstruction of temperatures including data collection, data pre-processing, calibration, validation and reconstruction.

The top of page 11 warns of the lowering of the reconstruction variability from the use of linear regression model for calibration and the uncertainty of the regression holding over the entire time period of reconstruction.

Re #206, Jasmine
Neither McIntyre nor McKitrick are physics drop-outs.
Please tell me you are not suggesting that your government should listen to Mann because he is American, but should ignore McIntyre and McKitrick because they are Canadian. Please tell me that is not what you are suggesting.

Not sure what happened to Jasmine’s comment #202 that fFreddy references, but assuming she really said what he quotes her as saying:

Jasmine, you say in #206 that the car you drive is irrelevant, but fFreddy quotes you as saying that discussions should focus on “pertient issues regarding energy self-sufficiency.” Isn’t the car you and everyone else drives pertinent to energy self-sufficiency? And if you’re offended by my comment about an SUV, I think you’ve been in the PC world of academics or government for too long.

By the way, if the Spam monster got you, I hope you don’t waste dozens of posts complaining about it. It happened to me too when I first started to post comments. It’s just the way it works.

I don’t drive a car (thanks for asking)… why the pertinent details of my personal life are so important to some of you are a bit beyond me. I hadn’t asked for the gender, transportation choice, or any other details of any others’ lives.

I’m used to environments where ideas matter and where we’re working towards a future in the face of some fairly pressing issues. I clearly stumbled into the wrong place here. My apologies.

Wouldn’t the world be a better place if OUR Honorable Members could spend their time discussing pertient issues regarding energy self-sufficiency instead of an ad hominem attack against a junior scientist from non-citizens who are “drop-outs from physics in little backwater places?”

And fFreddy replied:

Not sure what you are trying to say here. TCO’s reference to physics drop-outs referred to Michael Mann.
What did you mean by your reference to “non-citizens” ?

Just my guess but I think Dr. Mann was just demoted to junior scientist (damage control?) and those two Canadians to non-citizens (suggested intro for Lou Dobbs?).

Well I got my fingers rapped for encouraging people to digg Lubos’ article. I tend to take action, and think if the media won’t get the word out you have to do it yourself. Hopefully some of the bigger blogs will report it next week with the hearings, because the pickings apart from Lubos have been pretty poor. I think Lubos has written a useful article. It has links to the main documents. It has some thinking, and some humor.

I’m used to environments where ideas matter and where we’re working towards a future in the face of some fairly pressing issues. I clearly stumbled into the wrong place here. My apologies.

Don’t be sorry. I think many here would want to evaluate for themselves these places where ideas matter and all are working towards a better future. Do you have any places in mind that you would care to share?

The ball is NOT about an obscure letter (published in the last millenium) that has no bearing on scientific thought regarding the causation behind climate change.

More importantly, we are at war and it’s not looking like this ball game is going to get easier until we are no longer beholden to energy sources from societies that would (seem to me) to want to drive us back into the middle ages. As a citizen of the US, I am optimistic that the Honarable Members of Congress can devote some serious thought to this underlying issue.

I want to thank you all for an entertaining weekend. It was disheartening but informative. My unsolicited advice: pay attention to this millenium and not to obscure letters from the past one.

As a scientist, I’ll stick to the peer-reviewed literature regarding my own areas of climate science dynamics. I will continue to make public statements about climate dynamics where issues regarding my gender and sightedness are not hurdles I must pass.

I am wondering how the New York Times will handle this story. My thoughts:

* wait until the hearings, at which Henry Waxman will be the attack dog. Quote him.
* the story will discuss paleoclimatology as an infant science tackling a critically important subject. Speed is essential. 2006 so far is the warmest ever in the US (sixth warmest worldwide, but that’s an inconvenient fact, so focus just on the US).
* Mann’s report is said to have statistical errors but, per the NSC, the results (hockey stick) have been confirmed.
* Mann speedily tackled an important subject and, even with claimed errors, he acted on the behalf of mankind.
* Politicians should not be meddline in the processes of science.
* The Congressman is probably owned and operated by Exxon and other oil interests.
* If the calls to George Mason, Rice, etc, can reveal dirt on the investigators, toss that in, too.

This obsession I’ve witnessed over ancient history has been …ummm.. ODD to say the least!

The operative quote should be, “Those who cannot remember the past, are condemned to repeat it.” George Santayana – The Life of Reason 1905 I.e. if we cannot determine what mistakes were made, they will be repeated.

I think you will find Jasmine is commentating on the Joint statement of the combined academies of science at the SPB g8 meeting.The emphasis has now changed to technology,innovation,and development.

Ensure, in cooperation with industry, that technologies are developed and implemented and actions taken to protect energy infrastructures from natural disasters, technological failures, and human actions;
– Address the serious inadequacy of R&D funding and provide incentives to accelerate advanced energy-related R&D, also in partnership with private companies;
– Implement education programs to increase public understanding of energy challenges, and to provide for energy-related expertise and engineering capabilities;
– Focus governmental research and technology efforts on energy efficiency, non-conventional hydrocarbons and clean coal with CO2 sequestration, innovative nuclear power, distributed power systems, renewable energy sources, biomass production, biomass and gas conversion for fuels.

re: 237 (231) “This obsession I’ve witnessed over ancient history has been …ummm.. ODD to say the least!”
It’s simpler than that: Dr. Jasmine practices more than hypocracy (ad hom’s). Why is she here at a largely subject-related blog (bad practices and arguments in the AGW science community as represented and most prominently spearheaded by MBH9x)?

re: 229 “The issues concern nuclear power, innovative nano-technology storage sources, renewable energy sources, etc.”
Are you arguing these technology’s adoption and advancement rates are somehow enhanced by scary “new” AGW scenarios, as opposed to scary “ancient history” AGW scenarios? If so, such “ends justifies the means” arrogance is unnerving if not frightening. Do you actually believe these technology initiatives are better served by falsifying justification to the public; or if you prefer, offering up umproven scary scenarios in the hopes of stimulating demand? Then again, perhaps those not believing, or wanting to suspend/control such things as the law of supply and demand will benefit from the religious marketing of the hockeystick — but then that would be unfair for me to paint all AGW-proponents as anti-capitalism. But beyond that choir of anti-capitalists, the rest of us know that neither nuclear power nor nanotech, nor renewable fuels need AGW and it’s cost-ineffective IPCC or Kyoto-led CO2-limiting bureaucracy initiatives to progress.

But thanks to Dr. Jasmine anyway, for blowing sunshine where it wasn’t needed. If only one could generate aerosol/cloud-cover with such arguments, one could slow down GW regardless of forcing?

There are good arguments to focus on non-fossil fuel energy alternatives. That these will end (except coal) in the near future. And that one need to be more independent of not so stable countries (as again is proven nowadays) for geopolitical reasons. But if greenhouse gas emissions are a big player in this all is rather questionable. The problem is that current measures (like the Kyoto protocol) will not have any measurable effect but at a high cost, and are aimed to reduce CO2 without much funding for alternative energy initiatives (much of the money probably will benefit the Russian maffia…)

It is not very important that the HS was right or wrong in its conclusion. It is far more important that political decisions with a huge economical impact are based on the best science available. In this case, one of the pillars of the decisions is proven wrong, and many of the newer reconstructions are probably wrong, as they are based on the same disproven proxies. The effect of past variability on climate models, whatever the future scenario’s might be, is huge. Thus one need much better reconstructions of the past millennium/millennia to know what the real impact of natural variability on climate is (and thus what the real impact of GHGs is) and what the cost/benefit is of urgent or less urgent measures to reduce CO2 levels to near zero (which is the only effective goal if you believe that CO2 has a huge impact).

Perhaps in Jasmine’s thinking, we see the likely PR response to the exposure of Mann’s (and thus IPCC’s) non-science ‘science’…

The ball is NOT about an obscure letter (published in the last millenium) that has no bearing on scientific thought regarding the causation behind climate change.

Before:
* The HS was significant enough to be prominent in many publications.
* Mann’s methods and data were considered a significant part of AGW research.

To Jasmine:
* The HS is now obscure.
* Mann’s work has no bearing on scientific thought about AGW.

What’s fascinating is what she did NOT say.

Einstein was an obscure patent clerk who published some papers in the last millenium. If his work were ripped to shreds as Mann’s has been, a rather significant amount of 21st century science would be severely impacted. And if he were still alive under such circumstances, one would expect him to be called to account for his heinous errors.

* So what if Mann got it wrong in ’98? You don’t need to hurt his feelings! Quite bellyaching about it. After all, isn’t saving the planet more important than some obscure calculations the average Joe can’t fathom? Obviously, it’s hot, and we’ve gotta DO something about it!

* Look, Mann’s got interesting NEW work going on now. And lots of friends who think he’s great. And plenty of funding. So let’s just let bygones be bygones, and focus on IMPORTANT work. Who needs audits and auditors? You guys are boring. (No entertainment or shock value at ALL. C’mon!!! Did you really think an AUDIT would make prime time news?!!)

* And loosen up on this “careful science” and “need qualified statisticians” stuff. Looks like some bean counters are looking for more work, if you ask me. Obviously, the planet is warming up. If Mann and his friends have figured out some cool computer formulae that mirror today’s warming, more power to them!

–MrPete

(PS… curious about the statement:

until we are no longer beholden to energy sources from societies that would (seem to me) to want to drive us back into the middle ages.

Since it’s just been proven that we do NOT know about the ‘A’ in AGW, and there is much evidence that Kyoto et all will do no good at huge expense, it’s clear to me who it is that wants to “drive us back into the middle ages.”

One would think there would be a bit more opposition to spending ourselves into oblivion on useless initiatives.

Not sure if I’m hopeful or not, but I’m glad M&M are at least trying. Eventually, it would be nice to see some Real Science done. Even if the outcome is “sorry folks, we’re now quite certain that we have no way to know if we can impact natural climate variation. The world’s getting hotter for a while; let’s learn to live with it!”
Spending trillions in attempts to cool things off — with no knowledge of whether our actions will have the intended effect, opposite effect, or no effect — is the height of folly.

My unsolicited advice: pay attention to this millenium and not to obscure letters from the past one.

???
jasmine makes it sound so reasonable. MBH’98 is just an obscure letter, and not (as the nas panel said) a ground-breaking scientific paper which has spawned an entire field.

Wouldn’t it be so easy if we could just paint out the inconvenient bits of our history, just like 1984 ?

Back in the real world of science, Nature and Science papers are meant to meet standards; high standards. When they are shown to be fatally flawed, then that is a signficant issue. It has major repercussions for the field that has been spawned. Some of the other issues around MBH98 are equally deserving of attention, not least the self-serving approach to statistical testing.

Stephen Schneider of the National Center for Atmospheric Research described the scientists’ dilemma this way: “On the one hand, as scientists, we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but-which means that we must include all the doubts, the caveats, the ifs, ands, and buts. On the other hand, we are not just scientists but; human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climatic change. To do that we need to get some broadbased support, to capture the public’s imagination. That, of course, entails getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might. have. This `double ethical bind’ we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.” DISCOVER OCTOBER 1989, Page 47

Tim Lambert is still defending Mann’s method on JustOneMinute.typepad.com, claiming that the off-centering is immaterial and the PC can be retained thanks to Preisendorfer’s n. Hat tip MJW.
============================================

ENERGY: Wouldn’t the world be a better place if OUR Honorable Members could spend their time discussing pertient issues regarding energy self-sufficiency instead of an ad hominem attack against a junior scientist from non-citizens who are “drop-outs from physics in little backwater places?”

Wow. There’s a red herring, a straw man, two ad hominem circumstantials, and a quote out of context in the space of one sentence.

Jasmine — somehow I just know you’re actually still here — what you’re now complaining about is that a blog that is specifically about M&M’s criticisms of MBH’s papers on AGW is spending its time on M&M’s criticisms of MBH’s papers on AGW (and, of course, successive responses to that.)

I occasionally follow some knitting blogs. You know what? They don’t spend much time on energy policy either.

“Iraq the Model” mostly posts about life in Iraq, and almost never about carbon emissions. “Schneier on Security” devotes an inordinate amount of space to computer security, and almost none to energy policy.

Getting my point, or do I have to beat you over the head with it? What you’re complaining about is that the people here are blogging about topic A and you want to read a blog about topic B.

Which is just fine. Read Lynne Keisling’s blog, or start your own.

But I’m pretty sure that the people here are discussiing what they discuss here because that’s what they’re interested in discussing. Complaining about that is dumb and pointless.

You may have hit on the solution, H. Erren, Xeno’s Paradox. If someone nicks a half of your contribution, then a half of the remainder, where does it all end? What’s it all about, Alfie?
===========================================

It’s easy to understand why Mann et Al wouldn’t want to get real statisticians involved in this sort of paleoclimatological ‘evidence’. You don’t have to believe in a pro-AGW conspiracy to see what’s going on.

There are scientists out there whose job entails actually travelling to Antarctica or Outer Mongolia to recover various proxy samples, and / or actually spending the time to make and record measurements from proxy samples.

There are others, like Mann, whose job it is to sit in their office and massage other people’s data – and perhaps go on the lecture circuit.

Once real statisticians get involved in this exercise, Mann et Al, become superfluous and quickly lose their jobs. What would have happened if, eight years ago, Mann had gone to a Wegman and said, “I want to write a groundbreaking statistics paper with potentially significant public policy effect but I don’t know how to do it. If you do the work for me I promise I’ll mention you in the acknowledgements…”

I am sooo disappointed. I am in the camp of believing global warming is occuring and caused by humans, BUT I am open to other possibilities and I read EVERYTHING with scrutiny. So this report intrigued me, but it relys heavily on the statisticians that disputed the Mann paper. Although, the whole “clique” section was stupid. Pick any field and narrow it down (ie study of South American Sparrows) and there will be a “clique” or an interconnection between the experts. If there weren’t there would be no point, any moron that knew nothing about the subject could just write something up, with no peer review. No one publishes a scientific paper without either fully understanding the statistics or having it reviewed by a statistician. Unfortunately statistics can almost always be skewed either way. Anyway, I digress… I then looked into Stephen McIntyre (one of the authors quoted in this report and published disputing Mann, as a starting point.

The guy has been involved in mineral exploration for 30 years. Think there is a conflict of interest?
Also, the George C Marshall institute is funded by Standard Oil and Exxon (It appears most scientists that dispute global warming are connected to old GCMI) They have written such scientific gems as this;

This is an argument for the mentally challenged. “If a 50% increase in CO2 levels caused a 0.5C increase in temperature then a 100% increase in CO2 levels will only cause a 1.0C increase in temperature.” Yeah…if there is a direct 1:1 correlation in the most simple relationship (ie a 45 degree line on a graph), which no one has ever claimed. Then they go on to try to explain why it will actually be lower than that due to minor temperautre fluctuations within the noise of the 20th century. The author should be embarrased by his stupidity.

As I read more and more about global warming I find I am more and more convinced of the validity of the theory and the threat, and of the alterior motives of the people refuting it. It frightens me the number of uneducated people who either are too close-minded or too ignorant to really investigate the various reports, papers, funding sources and motives of the people making the arguments. I really wish this “Report” offered some sort of value to a false global warming theory, but it is really just more political hot air.

Before putting un-validated scurrilous accusations you might want to look into whether or not they have been discussed before, they have. Steve receives no financial backing for his work, and pays for this blog out of his pocket. So all you are doing is spreading un-substantiated ad-hominem attacks.

As to

“If a 50% increase in CO2 levels caused a 0.5C increase in temperature then a 100% increase in CO2 levels will only cause a 1.0C increase in temperature.” Yeah…if there is a direct 1:1 correlation in the most simple relationship (ie a 45 degree line on a graph), which no one has ever claimed.”

Your right, no-one has ever claimed this. They claim it is a diminishing log effect, meaning that a 100% increase will provide less warming based upon the physics of CO2 absorption. At some point it maxes out as absorption is saturated and no further warming occurs. Most likely I think you were challenged in reading the article and misinterpreted it.

but it relys heavily on the statisticians that disputed the Mann paper.

By which I assume you mean McIntyre & McKitrick. But that was the whole point of the report; who’s correct, Mann or M&M. Answer, M&M.

Also, the George C Marshall institute is funded by Standard Oil and Exxon

A. So what? who someone is funded by has nothing to do with whether the findings are correct or not. Again, that’s what the Wegman report was about and they, once again, said it’s M&M who are right.

B. It’s misleading; The Marshall institute may have received funding from them, but it’s a small % of their total budget. It’s nothing but an attempted ad hom on your part. Verry disappointing!

If a 50% increase in CO2 levels caused a 0.5C increase in temperature then a 100% increase in CO2 levels will only cause a 1.0C increase in temperature.

Actually a 100% increase will produce less than a 1.0C increase, not just because of any temperature fluxuations [i.e. natural variations], but because the CO2 absorption bands are largely saturated so that the increase in CO2 warming comes from increasingly marginal bands which require more and more CO2 to saturate. Thus temperature goes up with a roughly log of CO2 concentration. I assume you’re thinking of H2O positive feedbacks, but they’re not proven, probably small if they exist and also likely to peter out at some point since CO2 concentration has been hugely greater at various times in the past (though not in this interglacial AFAIK), and the earth’s temperature hasn’t heated out of control. [Though let me put in the disclaimer that undoubtedly it’s true that higher temperatures evaporate more H2O; the question is to what extent this is ofset by increased cloudiness, etc.]

the alterior motives of the people refuting it

Yes, well we skeptics do try to be up-front about our positions. It’s the warmers who want to hide both their data and their motives behind their backs. (I.e. thanks for the freudian typo – It should be “ulterior”)

Off-topic (admittably tired Jean S, not wanting to feed the troll): Where do these new “I-do-not-understand-anything-nor-have-I-anything-new-to-add-but-it-must-be-wrong-as-there-is-this-link-to-eXXXon-and therefore-I-comment-what-i-saw-over-DELTOID”-people keep coming here? Is it just me, but I feel like I’ve seen substancially the same comment as #248 dozens of times before, even in this thread. Are these people paid to comment?

uhohraggy: Steve Bloom, Tim Lambert, Carl Christensen, and dozens others whose names I’ve forgotten (sorry), have already educated this site about these issues, so please, read a bit more this site before repeating the same stuff. Even a stupid European like me knows already about “special interest groups”, “George C Marshall institute”, “wingnuts”, …

So this report intrigued me, but it relys heavily on the statisticians that disputed the Mann paper.

No, it relies on the statistics, which you obviously do not have the maths skills to understand. Which is one of the reasons why you are easy fodder for people marketing the AGW story.
In the absence of the intellectual skill to understand the arguments, it would also be wise to avoid sneering ad hominems about people’s backgrounds. Your eagerness to have someone to hate is another of the reasons why you are easy fodder for people marketing the AGW story.

However, if you think you are honest, I suggest that you should take a look at Professor Wegman’s resume. It’s pretty obvious that he is one of the country’s leading statisticians – after all, he’s Chair of the Committee on Applied and Theoretical Statistics, National Academy of Science. And he says that Mann’s work does not support his conclusions – i.e., the Hockey Stick is rubbish.

So, if you’re honest, you need to explain why you choose to believe Mann over Wegman.

Oh, and if you are going to make snotty comments about ‘uneducated people’, I suggest that you learn how to spell ‘ulterior’. (And ’embarrassed’. And ‘occurring’. And …)

Not my point Hans. Refer to UH’s comment about the effect being linear, he’s arguing, I assume, that it is Log increasing or some such, maybe he even believes it’s exponential, I doubt his argument is that it is decreasing with concentration. I understand saturation is included in the log effect, it’s kind of the definition, the point of complete saturation is irrelevant, the decreasing nature in reference to UH’s statement is.

uhohraggy,
Your message was so full of mischaracterizations and logical fallacies that I hardly know where to begin. OK, first your implication that Dr. Wegman and his associates on the Ad Hoc Committee were just rubber-stamping the findings of McIntire and McKitrick is just pain wrong. They waded into the debate between the Mann camp and the M&M camp, studied both sides (they did not “rely” on only one papper which is obvious if you had really read and understood the entire thing), applied their considerable experience and knowledge of applied statistics to the issue, and then wrote their report. The fact that they found Mann’s novel statistical approach flawed and supported M&M’s claims should not be surprising since Mann himself has admitted that he is not a statistician, nor did he consult one. Did you look at Dr. Wegman’s resume, or of his coauthors on the committee? They are obviously more than qualified to do this kind of analysis, after all Mann’s paper is all statistics. Just because you don’t like the answer does not make it wrong.

I’ll let others point out your other numerous errors and misstatements.

Where do these new “I-do-not-understand-anything-nor-have-I-anything-new-to-add-but-it-must-be-wrong-as-there-is-this-link-to-eXXXon-and therefore-I-comment-what-i-saw-over-DELTOID”-people keep coming here?

Jean, I think this is because the work that has transpired on these blog pages has threatened the entrenched belief system of AGW adherents. Without the HS, they are madly attempting to recapture the “proof” they had prior to M&M. The easiest method is to attack the source of their now lacking proof.

Unfortunately Mann’s hockey stick has been verified and re-verified again and again. I was actually looking for something scientifically sound to dispute it, but actually you all seem to fit the typical response. Let’s attack the spelling… not the science. I wasn’t arguing with their statistics, only that they weren’t always applied very well. As in the “clique” theory. Wish you were right. Go on fighting your windmills with your heads in the sand though. I’m sure you’ll all prove the world flat and that man never landed on the moon either. Best of luck to you

Re:#274
UH, you say: “Unfortunately Mann’s hockey stick has been verified and re-verified again and again.”
Would you care to list one or two studies that “verify” the HS while conforming to the NAS panel’s findings on appropriate use of proxies, etc (I’m referring to the recent NAS paleoclimate panel, not this Wegman report).

UH, you characterized posters here as: “Let’s attack the spelling… not the science.”
Valid point about the spelling (but you will give a better impression of yourself if you take a moment to check spelling before posting).
OTOH, in your only scientific argument (among many ad hominems) in the post, you implied that increased CO2 concentration would have a more-than-linear effect on temperature; you ridiculed a website as “Then they go on to try to explain why it will actually be lower than that …”
Most posters here DID respond to your scientific error, pointing out that an increase in CO2 concentration DOES have a less-than-linear (actually, approximately logarithmic) effect on temperature.

If you have any valid scientific arguments, please post them (the ad homs are neither helpful nor persuasive).

Response: I don’t see how the ‘battle’ has moved at all. There is nothing original in the Wegman report except the neat, but basically meangingless, social network stuff (I’m in a clique!), and so the scientific discussion hasn’t moved on one iota. In particular, Wegman completely fails to address the issue of whether any of these critiques ‘matter’ – which was the point of the earliest responses on this topic, here or in Rutherford et al, 2005, Wahl and Ammann (2006), or the NAS report etc. The answer was, and remains, no they don’t. They could have, but they didn’t. Them’s the breaks….- gavin]

I’m working on a trend of RC “dismissals” over time. In year 2005, it was “we’ve moved on.” In year 2006, it is “it doesn’t matter.” The trend tells me that in year 2007, it will be “it didn’t happen.”

The NAS report’s summary split the analysis into two kinds of evidence. The multiproxy reports, from Mann et al and its follow-ons, were limited by the NAS report to less than they originally claimed – the NAS committee ended up saying that the quantitative results of those analyses were solid going back 400 years, with decreasing utility because of increasing uuncertainty going further back to 900AD, and effectively unusable before 900 AD. Whel they acknowledged some statistical problems with those analyses, they also said that the primary reasons for the uncertainty were sparsity and uneven geographic distribution of proxy records as one goes further backin time. They DID limit the Mann et al global quantitative claims, but that was only one part of their report.

In the same summary, in adjacent paragraphs, they also pointed to many lines of additional evidence that independently support the conclusion that something anomalous was going on in late 20th century climate, on at least a millenial time frame. This includes quantitative evidence from high latitude and tropical ice cores (dealt with independently because of differing uncertainties), and qualitative (in terms of temps) evidence from things like global glacier ice balance and retreat, ice shelf collapse, observations of glacial melt in places where we have evidence that it hasnt happened in many thousands of years, evidence of rooted sub-glacier plants being uncovered for the first time in many thousands of years, and so on. These lines of evidence were covered in their own chapters in the report.

The report then says that the combined quantitative and qualitative data from this additional evidence supports the quantitative claim from the Mann and follow-on multiproxy studies that temps in the late 20th century were globally anomalous on millenial time scales. They specifically said that the quantitative multiproxy claims were plausibleeven if too uncertain in thero won context, and they did this in the context of all this additional suporting data showing something anomalous happening in the late 20th century.

MacIntyre/Wegman/etc HAVE shown some data source and statistical problems with various of the multiproxy studies – and are claimign they apply to later studies but have not done a good job of extending thair analyses to all the other later reports, so that part of the claim is IMO suspect. And will continue to be until the arguments are put together in some kind of comprehensive gathered form and subjected to review in that form.

But, (to get back to where I started this post) the NAS limitation and Wegman partial statistical criticism are being presented by a LOT of people as if they cut the legs out from any claims further back than 400 years, and by some ‘sceptics’ as if they cut off all evidence and any claims for anthropogenic causes for climate change. This is being done in many cases by behaving as if the Mann et al work was the only evidence that existed, or at least including ONLY mentions of that work in their analysis, and that leads to implications that are simply false.

[small snip]

The fact that the precise quantitative global results from the multiproxy studies have more uncertainty than previously claimed does NOT mean the millenial evidence for late 20th century cimate anomalies is not strong, even if the supporting qualitative data does not allow precise quantitative calculation of the global temps during those millenial time frames.

The committee has examined the facts and formed a surprisingly thorough analysis of the situation. The detailed review of the Hockey Team and its group-think is amazing. The utter failure of peer review must give pause to the leading publications. Do they dare continue with business as usual?

Dueling blogs may not be the appropriate media for “science” but I doubt that this stunning report would have occurred without them.

I’ve written an Op-Ed which Warwick Hughes has kindly agreed to host on weblogging, science and why I think Wegman may be wrong on this point.

Uhohraggy,
OK, you want to engage in the science, then fine, let’s give this another try. The scientific method states that theories can’t be ‘proven’ true. They can be tested, and if not falsified over time they are generally accepted as true and eventually become enshrined as ‘laws’ if they are really useful. However, it only takes one failure to falsify a theory regardless of how many times it’s been ‘verified’ (or more correctly, tested and not falsified). Mann’s novel statistical method of pulling temperature data out of these proxy records (tree-rings, ice-cores, etc.) has been proven, by a number of statistical experts, to be flawed, so his theory has been falsified. All other theories and papers that depend on his results or methods fall with it.

If you believe that the statistical experts are wrong, then please, by all means, present your case. Maybe you can show that the decentering in the calibration period does not affect the results. Or maybe you can show how Mann’s modifications to the standard PCA method somehow preserve the low-frequency information that is needed to make the conclusions he makes. Or pick your own issue, there seem to be plenty to choose from. I await your answer.

#287 Very good and strong Op-ed John_A. Another thing that could be added is the list of organizations that lined up behind Mann when asked to defend his behaviour (from RC).

# A statement from the EGU
# The American Association for the Advancement of Science (AAAS)
# A Nature editorial
# A letter from US scientists (including leading members of the NAS, a Nobel Prize winner and two of us (ES, GS))
# A letter from the head of the National Academy of Sciences, and
# A commentary from Tom Crowley in EOS
# Other politicians, the House Committee on Science and Henry Waxman.

Together with IPCC it paints a picture of gross-failure-of-our-scientific-instititutions.

In most places in the U.S. today, all it took to be an “ultra-warmer” was to walk outside. Be very worried, Dave.

Uh, hate to remind such a scientific mind of the obvious but the instrumental record shows only about 0.5C rise in the past 100 years, and only a few tenths since the “minimum” in the 70s. Also, most of the rise is at night. Therefore, “just walking outside” ain’t gonna cut it. Of course, you know that anectode is meaningless in a chaotic system, right? 🙄

OK, looks like we need something to take our minds off of Wegman until the hearings. I suggest a guessing game about the authors of the recent paper whose abstract reads as follows:

“Using a combination of proxy records and results of a three dimensional climate model, we show that European summer temperatures roughly a millennium ago were comparable
to those of the late 20th century. Those two relatively mild periods are separated by a rather cold era, 5 supporting the existence of a summer “Medieval Warm Period” in Europe. The long-term temperature history appears to result from the superposition of various anthropogenic forcings, the summer cooling associated with changes in landuse over the last 1000 years having the same magnitude as the net warming due to the
combined increase in greenhouse gas concentration and in sulphate aerosols during 10 the last 200 years. Volcanic and solar forcing plays a weaker role in this comparison
between the late 20th century and the early second millennium. Evidence for winter is more equivocal. The forced response in the model displays a clear temperature maximum
at the end of the 20th century but the uncertainties are too large to state that this period is the warmest of the past millennium in Europe in winter”.

Current European summer temperatures comparable to a thousand years ago? The current termperature “mild”?

Re: #285
“In most places in the U.S. today, all it took to be an “ultra-warmer” was to walk outside.”
Come on, SB, even the RC folks have denounced that fallacy. You don’t want to leave folks with the impression that you don’t have any valid scientific arguments.

#287 Very good and strong Op-ed John_A. Another thing that could be added is the list of organizations that lined up behind Mann when asked to defend his behaviour (from RC).

# A statement from the EGU
# The American Association for the Advancement of Science (AAAS)
# A Nature editorial
# A letter from US scientists (including leading members of the NAS, a Nobel Prize winner and two of us (ES, GS))
# A letter from the head of the National Academy of Sciences, and
# A commentary from Tom Crowley in EOS
# Other politicians, the House Committee on Science and Henry Waxman.

Together with IPCC it paints a picture of gross-failure-of-our-scientific-instititutions.

Actually that’s the most remarkable thing of all. That these august scientific bodies lined up to decry anyone from requesting that a scientist show his data and methodology.

Colorado State University’s celebrated hurricane predictor, William Gray, has thrown his chips behind the anti-ACW position

Here’s a Denver weekly’s article built around him and other prominant Colorado-based researchers in climatology.

In my opinion, this detailed portrait accurately conveys the complexity of the scientific debate and personal perceptions of personality that roil the field. It’s concluding mis-characterization about the June NAS report, cliaming that is bolstered the pro-ACW position, I corrected in a letter published in mid-July (also at the above site).

Now, as to whether the Wegman report comfirming M&M’s critique constitues “a nail in the coffin” of ACW, It’s only one – or in the broader scheme may only amount to half of one.

You’ll notice in the article above how much wieght pro-ACW’ers hope polluting aerosols may save the theory. The trouble is that the historical data collected is – as in paleclimatology – too dodgy. Thus, only future and ongoing research to precisely measure the phenomemon will clarify matters – much as corrections on satellite based temp measurements are now undergoing debate.

But the net results of all three debates will be to put the focus back on the data, instead of a priori theories, where it belongs! Kudos, Steve!

#287. Lee, whlie I don’t agree with everything that you say, thank you for your thoughtful post. It has taken me nearly two years and much effort to get supporting data from Esper. If you can imagine, I still don’t know even what sites were used in Briffa et al 2001. As I’ve mentioned before, I think that the NAS panel report clears the air for dealing with some of the other studies and hope to do so in the near future.

Admittedly, I possess virtually no expertise in science. That puts me in exactly the same position as most dogmatic environmentalists who want to craft public policy around global warming fears”

And I like this:

“Al Gore (not a scientist) has definitely been heard
—- and heard and heard. His documentary, “An Inconvenient Truth,” is so important, in fact, that Gore crisscrosses the nation destroying the atmosphere just to tell us about it. ”

Gore clearly spent the time to read and learn a lot about the science. This columnist clearly and admittedly has not. His ad hom about ‘dogmatic environmentalists’ with some power to craft public policy is unsupported. His ad hom against gore ignores the well-publicized fact that Gore has purchased carbon offsets to more than cover the carbon cost of his activities – and is irrelevant to the science.

Lee, starting on page 11 of the NAS report, we see that the committee is not at all confident of the use of long term temperature reconstructions before 1600 A.D. (see excerpt below). (Also, remember their warning that using a regression for calibration of the temperature proxy tends to reduce the proxy variation). That part of the report means we are all back to agreeing about the LIA and recent warming.

Both the number and the quality of the proxy records available for surface temperature reconstructions decrease dramatically moving backward in time. At present fewer than 30 annually resolved proxy time series are available for A.D. 1000; relatively few of these are from the Southern Hemisphere and even fewer from the tropics (Figure O-2). Although it is true that fewer sites are required for defining long-term (e.g., century-to-century) variations in hemispheric mean temperature than for short-term (e.g., year-to-year) variations, the coarse spatial sampling limits our confidence in hemispheric mean or global mean temperature estimates prior to about 1600 A.D., and makes it difficult to generate meaningful quantitative estimates of global temperature variations prior to A.D. 900. Moreover, the instrumental record is shorter than some of the features of interest in the preindustrial period, so there are very few statistically independent pieces of information in the instrumental record for calibrating long-term temperature reconstructions.

On page 22 of the NAS report the committee finally acknowledges that large-scale surface temperature reconstructions for the last 2,000 years are not the primary source for evidence of AGW. The primary evidence for AGW is given by the committee as the large increase in carbon dioxide and other GHG levels in the atmosphere starting in the mid 19th century along with the concomitant increases in instrumental temperature measurements and proxy changes during that time and the results of climate model calculations. That puts the whole debate right back to where it started and to skeptic like myself it yields no stated statistical probabilities in these propositions being correct.

Whatever makes you happy Lee. But the man is entitled to his opinion.
You can decide what you think about it. He has that right, like all of us do to express it right or wrong. It’s also his job. You don’t have to read it.

Besides, there’s probably thousands of articles that support the opposite written by non-scientists. So with your logic, they should not be written either.

About that OT Wegman report – there are some good responses to it floating about. Please choose wisely.

Hah! I’m yet to see one, can someone provide a link? Yes, I’ve seen the desperate non-responses by Mann, Lambert, Connelley, and Quiggin, but is there actually a response that contains also some substance?

In my opinion, this detailed portrait accurately conveys the complexity of the scientific debate and personal perceptions of personality that roil the field. It’s concluding mis-characterization about the June NAS report, cliaming that is bolstered the pro-ACW position, I corrected in a letter published in mid-July (also at the above web site).

Now, as to whether the Wegman report comfirming M&M’s critique constitues “a nail in the coffin” of ACW, it’s only one – or in the broader scheme may only amount to half of one.

You’ll notice in the article above how much weight pro-ACW’ers hope polluting aerosols may save the theory. The trouble is that the historical data collected is – as with tree rings in paleclimatology – too dodgy. Thus, only future and ongoing research to precisely measure the phenomenon will clarify matters – much as corrections on satellite based temperature measurements are now undergoing debate.

But the net results of all three debates will be to put the focus back on the data, instead of a priori theories, where it belongs! Kudos, Steve!

I wonder how MBH 99 would have been received if it had said the “1990s are likely the warmest decade, and 1998 the warmest year in at least a millennium” [except for Europe where the current temperatures are similar to those 1000 years ago. Please note we consider both the current temperatures and the Medieveal Warm Period to be mild]?

Without agreeing to the methology employed in this study, we can also note they state “there is no compelling evidence
from either empirical proxy evidence or model simulation results that late 20th century European summer temperatures were the highest of the past millennium”.

In characteristic modesty, the authors don’t hestitate to point out some undertainty: “the uncertainties are still too large to argue with a reasonable confidence that the highest winter temperatures of the past millennium were observed during this period”.

I don’t know why those Europeans should be the lucky ones not to be having the highest temperatures in the past millennium, while the rest of us fry. How did all that heat managed to stay just in Europe, while in the case of bristlecones, it managed to travel around the world? Just one more of science’s many mysteries I guess.

In the present study, we describe a plausible solution to this conundrum.

Just started reading the article but the above sentence jumped out. Let me suggest a plausible solution to the conundrum which is likely not the one they’ve come up with: There aren’t Bristlecone pines in Europe.

Is it my imagination or is this Goosse et. al. basically just saying they create a bunch of plausible model parameterizations, pick the one which most closely matches the proxy data in europe and then assume they’ve verified both the model and the proxies? This isn’t science, it’s big kids playing computer games!

And what about their uncertainty test, throwing out one proxy (at a time) and seeing how the selection changes? Is that really a statistically valid way of testing?

I’m done reading it now, and very unimpressed by this article. I suppose at some point Steve M and others will actually deconstruct it, but this looks to me like just another case of finding the Easter egg you hid yourself.

The NAS report to me says on one hand that the results from long-term proxy temperature reconstruction (all, not just Mann’s work) include much uncertainty and gives much evidence that at least one group used flawed statistical methods, but on the other hand computer models (at least some and at least some of their runs) and these flawed studies agree in general terms on historical temperatures and temperature variations.

On the uncertainty of reconstructions, the NAS committee on page 82 of their report emphasizes that predictions of temperatures from regression will have less variability than actual values, but that attempts to overcome this problem using alternative statistical approaches leads to losses in accuracy. Taken together their concerns sound close to giving an inherent limitation to such methods.

It is my understanding that climate models can be tuned or calibrated with instrumental data and long-term climate reconstructions. From the NAS report I was unclear how interrelated and interdependent the climate models that they cited were to the long-term reconstructions. I also found nothing on the performance of computer models tuned/calibrated with instrumental temperature measurements in predicting past temperatures based on long-term temperature reconstructions.

I was also curious as to how the climate modelers adjust for the number of fine tunings they use to get a reported fit, as in Bonferroni multiple significance testing, knowing that that can be very tricky business. Could it be that they contend that their models are or cannot be subjected these statistical methods, since they start from basic physics? Surely they have considered the Bonferroni problem, even if not directly applied to significance testing, but after the Wegman report on the lack of consultation of climatologists with statisticians I am not so sure.

I’m not sure what proxies are being used in Loosse et. al. above. My first guess is that it’s the ones from Luterbacher 2004 but does someone know for sure? In any case, are they any or our old familiars or some purely local proxies? From what I read there are only 14 proxy series, so it shouldn’t have killed them to tell us their names somewhere in the paper but I don’t see ’em.

I am reading the Wagner Report and one conclusion I made is that since both tree rings are a high frequency indicator of temperature but have a low frequency autocorrelation due to the growth of the previous year that Mann should of used a moving average model to relate tree rings to temperature. Auto regressive is not necessary because I don’t think the correlation length is that long.

I think that the moving average model should have been obtained by calibrating to local temperatures and only once a good model is developed of how tree rings relate to temperatures in local climates should Mann have tried to weight the temperature estimates from each proxy via his principle component analysis.

It’s my ignorant but considered opinion that animal and vegetable metabolism has converted a huge amount of carbon to mineral in an ongoing process of carbon sequestration; and that we are kept on the cusp of glaciation by the action of water vapor, and gradually increasing insolation.
=========================================================

RE: #266 – RC were claiming that the “de facto thermal resistance” effect of CO2 would increase (linearly?) with PP CO2 clear up to 1000 ppm. I have no idea what their basis was for that pronouncement.

Geoff,
There are time when it is difficult for me to resolve proxy data with what I know about atmospheric science. Mann for instance says that the LIA and MWP were only regional events at best, and were not indicative of the global climate in general. So, while Europe warmed for 500 years, the rest of the world must have remained remarkably cooler. And while, Europe cooled for 400 years, the rest of the world must have been remarkably warmer. For the past 150 odd years the entire globe has warmed consistently. I guess the big question is, if Mann is correct, how can he explain that for 900 years a large part of the Northern Hemisphere warmed and cooled as if it was its own climate system? If GHG are the reason why we have warmed since 1850, why did Europe, Iceland, North Africa, and Greenland warm so much and for so long, while the remainder of the globe remaind so much cooler? It makes absolutely no sense.

Teleconnections do not expalin what Mann says occured. ENSO doesn’t act that way. The globe doesn’t store heat in such large amounts in such high continental latitudes (Europe or Eurasia).

The “warmers” still refuse to say that we just don’t know yet what is happening. Now that the HS has been splintered beyond all recognition, the “warmer” position is now becoming: “Maybe there was a MWP and LIA, but warming is taking place MUCH FASTER this time, signifying that evil CO2 molecule is causing it.” Gawd, they always find a new justification for panic. It is hillarious!

Re #333: JP, I agree that the very idea that Ireland might be quite a bit warmer than Labrador must palpably violate one’s innate sense of latitudinal climate consistency. It’s an outrage, I say, and we should refuse to listen to any explanation for it.

Re #334: jae, there are all kinds of bases for alarm. A certain well-known statistician, for example, is alarmed at the current rapid uptake of heat by the oceans.

The warmers are not as morally correct as we are. They are not so virtuous. They would not be the cell mate that you would want in the Hanoi Hilton. They are little liberal pussies. Plus they have long hair.

Dave, the proxies used are described in chapter 3, page 291. Two Europe-wide reconstructions (Luterbacher e.a. 2004 and Guiot e.a. 2005), the others are more regionally oriented. Several proxy series used in Luterbacher e.a. are tree ring series, one of them the notorious Yamal series, which probably lowers the overall variability (compared to the updated Polar Urals series)…

Some more remarks: for solar forcing, they used the Lean e.a. and Bard reconstructions. The Hoyt & Schatten reconstruction wasn’t used. Remarkable is that they used a model which has a quite low sensitivity: 1.8 C increase for 2xCO2, near the lower end of the IPCC range.
Further, I have some doubts about the weight (forcing and/or sensitivity) that is given in all models to land use change at one side and to GHG/aerosols at the other side. For the latter, there is a huge change in aerosol emissions in Europe (an over 50% drop in SO2 emissions since 1975), but that is not visible as a difference in temperature trends of stations up and downwind of the largest emissions. See my comments here

So the proxies are actually all reconstructions of various sorts? Curiouser and Curiouser. Well, this ought to keep Steve M busy for a while if these regional reconstructions each have many components.

I think I am violating some etiquette rules of the Web by replying to myself, but if anyone wants to jump in I would appreciate it and particularly to correct where I might have strayed from others’ views of the NAS committee messages and computer modeling. It is the only place where I do not receive stares when I talk to myself.

I wanted to make the additional notation that the NAS report seemed rather defensive when it comes to the issue of AGW in a general sense, but at the same time clearly describes all the uncertainties and pitfalls of using long-term temperature reconstructions. I only wish that they would have been more detailed in their accounts of climate modeling and the effects of volcanic aerosols.

They did make the non-controversial call on the LIA and current temperature increases over the past 400 years from proxy reconstructions in rather definitive terms and then were vague and uncertain for reconstructions for the time period before that period. In showing that temperatures can decline* takes as much defending as would a “natural” temperature increase, if one wants to maintain the view of the recent temperature increases as AGW. The report indicates that the temperature decline for the LIA is attributed to aerosols occurring from volcano eruptions. (They apparently agree that the Maunder Minimum was not a major contributing factor). One could than argue that the current temperature increase is due to a subsiding of aerosols from volcanoes and thus weaken the case for carbon dioxide induced AGW. The NAS committee attempted to show that not to be the case.

My question then is: How strong is the case for aerosols? I did not see any major attempt for quantifying these effects from the NAS report.

*Looking at the the millennial temperature reconstructions on page 2 of the NAS report one can see perhaps why dealing with only the last 400 years makes explanations less complicated: you do not need to find “natural” causes for such large temperature changes. Apparently only the Mann/Jones reconstruction (with the HS) avoids this problem.

Re: #340
RC has decided to create a side forum to keep pesky topical subjects like the NAS report off the main page and out of the sight of casual visitors there. They asked for comments on this plan, so I asked whether the side forum would be moderated/censored like the main one; given the disappearance of that and another post, it seems the answer is “yes.”

Ken, volcanic aerosols can have a huge, but temporarely influence on climate. The Pinatubo eruption was really huge, with a VEI (volcanic explosion index) of 6, of which there were only 9 in the past 600 years. Only the Tambora eruption (1816) was stronger with VEI 7. See Fig. 6 of the Briffa reconstruction.
The net effect of the Pinatubo was a global cooling peaking at ~0.6 C and lasting not more than 3 years. All together, volcanic explosions in the past 600 years in average have had less than 0.1 C cooling influence. Even that may be more than real, as trees (used in Briffa) not only respond to cooling, but also to reduced sunlight due to aerosols in the growing season, if that is a limiting factor. The Pinatubo makes a rough estimate of the (primary) effect of human emitted aerosols possible, see my comment at RC

The remaining temperature variation (0.1 C for MBH98/99, 0.7 C for Moberg) in the reconstructions is natural variation, other than volcanic, mainly solar. That means that any attribution based on MBH98/99 quite certainly underestimates natural (solar) variability…

One of the less attractive instincts of Homo sapiens is to have a monopoly on property, power, justice and ideas. History is full of examples, some recent, of the disastrous consequences of such monopolies. Science has never been excluded from this tendency. Newton was every bit as self assured as Michael Mann and Fred Hoyle did not exactly welcome Stephen Hawkins’ new ideas. Much of what we call civilisation is structure that has developed over time to limit monopolies.

In the past it mattered little whether there was balance or “self reinforcing networks” monopolising particular fields since the consequences of great scientific debate did not reach outside their community until the science was demonstrably settled such as radio communication, the atomic bomb and the transistor.

I will no doubt be slammed for saying so but AGW is more like politics or religion in that the absolute truth is unlikely to be manifest in our lifetime. What is sad is that with all our experiences of dictatorships and religious hegemony we in Europe have the least tolerance in this matter. The unique nature of AGW theory with drastic consequences if we get it wrong mean that we should encourage and indeed fund skeptics and require full disclose from all working in the field.

Let me add my few cents here. The article made me deeply sad. Although the facts are mainly true (European vs. US media coverage), the sad thing is that these interviewed journalists really seemed to yearn for the media where all the dissenting voices are suppressed for the “common good”. This is an extremely scary and dangerous attitude giving me grim echos from the past: I’ve seen it in action and I don’t want to experience it again. The society is no longer free, if the marginal voices are suppressed, no matter how “good” the reason is. No matter if there is a unambiguous “consensus on foreign policy” or a unambiguous “consensus on climate change”. A thing to learn from our past: when you hear every day media chanting “consencus” on something… it’s a big lie! If it were true, there would be no need to repeat it all the time.

Paul D. Thacker and other similarly minded people, I challenge you to think hard about it: would you really want to live in a “1984”-society?

Thoughtful post, Jean S. Leftism/Marxism never died — after hiding out in the usual bastions of such — political, media & educational institutions, they’ve slithered out into science fields in the last decades to advance their agendas. As bad as it is here in the US, in many ways some of Europe is farther along on this dangerous path.

Funny, neo-Marxist/post-modernists never seem to be found in the competitive & results-dependent business & industry world, or any situation where there is a strong accountability.

RE: #258 – “As I read more and more about global warming I find I am more and more convinced of the validity of the theory and the threat, and of the alterior motives of the people refuting it. It frightens me the number of uneducated people who either are too close-minded or too ignorant to really investigate the various reports”

I am a degreed scientist, with over 20 years of experience working in high technology. One of the selling points of current products I work on is “greenness” and “carbon emission reduction.” And yet, I find the work of M and M to be more valuable than the sum total of what the Hockey Team have done. Even if it is eventually proven that essentially, AGW, in a scenario not far different that that purported by the climate science orthodoxy, is in fact the key reality, what M and M have done will have gotten us to the point of proof far more than all the collective arm waving of the Hockey Team over the years.

Probably not a good time to do this with the blog’s attention focused in another direction, but I want to state that I much appreciate your reply, Ferdinand Englebeen, to my query of the temperature effects of volcanic aerosols. I will re-review the NAS committee report on this subject with your comments in mind and do some further searching of my own.

You also said in your reply:

The remaining temperature variation (0.1 C for MBH98/99, 0.7 C for Moberg) in the reconstructions is natural variation, other than volcanic, mainly solar. That means that any attribution based on MBH98/99 quite certainly underestimates natural (solar) variability…

Agreed and to me seems to demonstrate a perhaps overly zealous attempt to minimize the natural variability in order to make a better case for AGW.

I hope you will forgive a complete stranger posting here, but I came across this site, almost by accident. I have been interested in GW for many months, and have come across a question that I cannot find an answer to, nor can I find anyone to talk to about the subject. I was in touch with Gavin Schmidt at one time, but he was no help. I am looking at Myhre et al 1998 New Estimates of Radiative Forcing due to Well Mixed Greenhouse Gases; Geophys. Res. Lett. 25 14 pp2715-2718; specifically Fig.1. This shows the change in radiative forcing for concentrations of CO2 from about 280ppmv upwards. What I want to find out is, using the same methodology so that the results are comparable, what is the change in radiative forcing between 0 (zero) ppmv and 280 ppmv? If anyone can provide an answer, or direct me to a forum where I might find the answer I would be most grateful. If it is not too rude on my part, could anyone who thinks they can help please contact me at bf906@ncf.ca. TIA.

the whole “clique” section was stupid. Pick any field and narrow it down (ie study of South American Sparrows) and there will be a “clique” or an interconnection between the experts.

I agree with this. What is missing from this part of the Wegman Report is some sort of benchmark as to how “cliquey” research groups are on average so we can determine if the Mann clique is more “cliquey” than it should be. People who know anything about academia know that researchers tend to repeatedly write papers together and that they tend to review each others’ work. This is natural, and while it obviously tends to let lousy work get published more easily by the clique members, there has been no determination that this bias is any worse here than it is anywhere else.

With regard to your comment about motives, you should also take into account the distortions of Mann’s incentives. Think about it. He publishes a paper that pretty much everyone now agrees was garbage, he makes a big name for himself and since it took eight years to show his paper was garbage, he safely has tenure and a coterie to defend him. That is a pretty strong incentive to publish lousy research with the “right” results to get into the clique.

I hear that, behind his back, Mann is increasingly being referred to as “Piltdown Mann.”

Is this really true (or are you just trying to make it true)?

I am actually serious about this. Actual climate scientists know what is what in this debate — they can read the papers and understand the issues. He may be at a tipping point where he is an embarrassment to the profession and people don’t want to be associated with him.

There seem to be hints of this. The party line now seems to be “Mann’s evidence plus reliable evidence of AGW adds up to reliable evidence of AGW.” (Hat tip to Steve Bloom for making this clear.)

Actual climate scientists know what is what in this debate “¢’¬? they can read the papers and understand the issues.

With respect, then how come peer review of MBH9X failed so catastrophically ?

With reference to the social network thing, I don’t think Wegman’s starting point was “Let’s look at this review community and find a way to be rude about it”. Rather it was “I have just found that this review community has failed to do a proper review. Let’s have a look at why.” Or maybe that’s just my interpretation.

With respect, then how come peer review of MBH9X failed so catastrophically ? Surely this implies that either your statement is incorrect, or else it is correct in which case the “actual climate scientists” have been downright fraudulent ?

Peer-review is actually quite weak in finding the type of flaws infesting MBH9x, and standards of publication are actually quite low. The criterion is more “does it contribute ANYTHING” than “is it completely correct in all its details.” Since most of the flaws were well hidden and even the procedures themselves obscure, there was no way for a typical peer-review to find them. That is why it took so long to dig into it.

Also, keep in mind the incentives. Eveyone wants to publish, and there is way too much journal space looking for articles in comparison to the number of good papers out there. each person’s incentive is to keep the publication threshold low so that their marginal papers get published, and if this means that a lot of other marginal papers get published, then that is a small price to pay.

This is also why the climate journals may very well never come to openly repudiate Mann. He is quite powerful now and has established a repuation for vindictiveness. Your criticise him at your peril. For a young academic and for politically ambitious academics, criticising Mann gets you little and creates a substantial risk. It will tend to be the older, don’t-give-a-damn academics that will carry the ball. Academics in other fields may also be able to get some quick publications by picking the low hanging fruit of correcting Mann. It is possible that we will see a series of papers in statistical journals correcting Mann.

Terry I think that there will be interest from stats and signal processing folks in the low hanging fruit. Someone already mentioned the late breaking session at the jsm including Wegman and Nychka. I bet a lot of grad students are just now taking their first look at climate science.

I’ve found that it’s best to leave a space between your link or quote before closing a tag. I’ve never had one run over when I do it that way and so I’ve just made it automatic. I hit, say, b-quote, then the space bar then ctl. v then the space bar and then close b-quote.

Regarding John Daly. My initial exposure to the global warming / climate change was rather upsetting.

About 12 years ago I was asked to prepare a procedure for measuring and reporting greenhouse gas emissions. Why wass this needed? The literature I was presented was shocking leading to many months of anguished soul searching and a questioning of my education, my moral fibre and ethical grounding. How could we have screwed up so badly? I needed to find out and the internet was one conduit to information and hopefully a better understanding.

I stumbled across John’s web page by accident. It was an education that lead to other places and eventually here. John Daly may eventually be considered to be one of the more influential people of the late 20th century. History will tell. It usually does.

Regarding the so called demise of AGW.

“It is not the End; nor is it the Beginning of the End; But perhaps it is the End of the Beginning”

I think Daly’s point of how the instrumental is appended to the recons (in such a manner that you can’t read recent recon history) is still a big part of the hockey stick. Look for instance at the southern hemisphere Mann and Jones 2003 piece. All of these things look much less dramatic if proxy only is shown. But if proxies can’t really track with recent warming, how can they tell us old warming?

On the Wegman report. Something I was wondering. If it pushes any distinct shape to the PC1 (for instance the MWP of IPCC2) out of a network of other noise, what does this mean? Is it like a magic low freq detector? eVen if only 1 of 70 series have that low freq signal? Should we put this thing into sonars or something, since it is so good?

Regarding 364 (Jeff Norman) “history . . . usually tells.” No, it doesn’t, despite the seemingly undeniable logic of it. Suppose global temperature goes down from here. Would that disprove anthropogenic warming? No, but it might set some limits to its presumable magnitude. Suppose temperature goes up from here, with continued increases in CO2 concentration, etc. Would that prove it? Not necessarily. Say temperature goes up with DECREASES in CO2 concentration (as it has in the past). In that case, see first scenario above. I’m afraid we’re dealing here with a system so complex that at least at our present (contentious, duplicitous?) state of understanding of it, we’ll be in no more position to draw conclusions than we are now. If the science improves (even if just in its freedom from normative influences)? Well, that’s to be hoped for, and it MIGHT disclose the retrospective truths Norman hopes for. At that juncture, only historians would care, but the few among them who are like me might care VERY MUCH.

On duelling weblogs:
What do you think scientific research labs – including Wegman’s – in the ivory tower do during lunchtimes and after hours over beer? They argue freely over the latest papers, often with someone acting as secretary to record the flow of ideas ot figure out what future directions the lab should take. As John A points out, the internet makes that discussion globally inclusive. The only institution threatened by this innovation is the institutional monopoly of Big Science over information flow.

I’m fine with weblogs in addition to real science. But not instead. It’s easily evident that people put more care into writing a paper then into a blog post. Plus the systems of editors and peer reviewers add value as quality screens for science and for writing. In addition, there are the issues of record-keeping and abstracting and the like.

An intersting thing is to look at the CPD paper by BC and the discussion on it. BC (one of them) admitted that the paper was poorly written and (part of) the reason for that was condensing it into GRL length. Now don’t get me started on letters, that is another abomination. But the interesting thing is that they thought so little of CPD that they did not rewrite the paper once length limits no longer an issue. And who does this hurt? Who does it show disdain for? THE READER.

John A: I would like to emphasize that the following is my personal view and not necessarily that of Steve McIntyre or Ross McKitrick.
In amongst the consideration of the proxy, statistical and social network evidence of the Wegman report, there is als…